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Patch "[Variant 2/Spectre-v2] arm64: KVM: Use per-CPU vector when BP hardening is enabled" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 2/Spectre-v2] arm64: KVM: Use per-CPU vector when BP hardening is enabled to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Marc Zyngier <marc.zyngier(a)arm.com> Date: Wed, 3 Jan 2018 16:38:35 +0000 Subject: [Variant 2/Spectre-v2] arm64: KVM: Use per-CPU vector when BP hardening is enabled From: Marc Zyngier <marc.zyngier(a)arm.com> Commit 6840bdd73d07 upstream. Now that we have per-CPU vectors, let's plug then in the KVM/arm64 code. Signed-off-by: Marc Zyngier <marc.zyngier(a)arm.com> Signed-off-by: Will Deacon <will.deacon(a)arm.com> Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Conflicts: arch/arm/include/asm/kvm_mmu.h arch/arm64/include/asm/kvm_mmu.h Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm/include/asm/kvm_mmu.h | 10 ++++++++++ arch/arm64/include/asm/kvm_mmu.h | 38 ++++++++++++++++++++++++++++++++++++++ arch/arm64/kvm/hyp/switch.c | 2 +- virt/kvm/arm/arm.c | 8 +++++++- 4 files changed, 56 insertions(+), 2 deletions(-) --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -221,6 +221,16 @@ static inline unsigned int kvm_get_vmid_ return 8; } +static inline void *kvm_get_hyp_vector(void) +{ + return kvm_ksym_ref(__kvm_hyp_vector); +} + +static inline int kvm_map_vectors(void) +{ + return 0; +} + #endif /* !__ASSEMBLY__ */ #endif /* __ARM_KVM_MMU_H__ */ --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -309,5 +309,43 @@ static inline unsigned int kvm_get_vmid_ return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8; } +#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR +#include <asm/mmu.h> + +static inline void *kvm_get_hyp_vector(void) +{ + struct bp_hardening_data *data = arm64_get_bp_hardening_data(); + void *vect = kvm_ksym_ref(__kvm_hyp_vector); + + if (data->fn) { + vect = __bp_harden_hyp_vecs_start + + data->hyp_vectors_slot * SZ_2K; + + if (!has_vhe()) + vect = lm_alias(vect); + } + + return vect; +} + +static inline int kvm_map_vectors(void) +{ + return create_hyp_mappings(kvm_ksym_ref(__bp_harden_hyp_vecs_start), + kvm_ksym_ref(__bp_harden_hyp_vecs_end), + PAGE_HYP_EXEC); +} + +#else +static inline void *kvm_get_hyp_vector(void) +{ + return kvm_ksym_ref(__kvm_hyp_vector); +} + +static inline int kvm_map_vectors(void) +{ + return 0; +} +#endif + #endif /* __ASSEMBLY__ */ #endif /* __ARM64_KVM_MMU_H__ */ --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -52,7 +52,7 @@ static void __hyp_text __activate_traps_ val &= ~(CPACR_EL1_FPEN | CPACR_EL1_ZEN); write_sysreg(val, cpacr_el1); - write_sysreg(__kvm_hyp_vector, vbar_el1); + write_sysreg(kvm_get_hyp_vector(), vbar_el1); } static void __hyp_text __activate_traps_nvhe(void) --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -1158,7 +1158,7 @@ static void cpu_init_hyp_mode(void *dumm pgd_ptr = kvm_mmu_get_httbr(); stack_page = __this_cpu_read(kvm_arm_hyp_stack_page); hyp_stack_ptr = stack_page + PAGE_SIZE; - vector_ptr = (unsigned long)kvm_ksym_ref(__kvm_hyp_vector); + vector_ptr = (unsigned long)kvm_get_hyp_vector(); __cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr); __cpu_init_stage2(); @@ -1403,6 +1403,12 @@ static int init_hyp_mode(void) goto out_err; } + err = kvm_map_vectors(); + if (err) { + kvm_err("Cannot map vectors\n"); + goto out_err; + } + /* * Map the Hyp stack pages */ Patches currently in stable-queue which might be from marc.zyngier(a)arm.com are queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

7 years, 4 months

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Patch "[Variant 2/Spectre-v2] arm64: KVM: Make PSCI_VERSION a fast path" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 2/Spectre-v2] arm64: KVM: Make PSCI_VERSION a fast path to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kvm-make-psci_version-a-fast-path.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Marc Zyngier <marc.zyngier(a)arm.com> Date: Wed, 3 Jan 2018 16:38:37 +0000 Subject: [Variant 2/Spectre-v2] arm64: KVM: Make PSCI_VERSION a fast path From: Marc Zyngier <marc.zyngier(a)arm.com> Commit 90348689d500 upstream. For those CPUs that require PSCI to perform a BP invalidation, going all the way to the PSCI code for not much is a waste of precious cycles. Let's terminate that call as early as possible. Signed-off-by: Marc Zyngier <marc.zyngier(a)arm.com> Signed-off-by: Will Deacon <will.deacon(a)arm.com> Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm64/kvm/hyp/switch.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -17,6 +17,7 @@ #include <linux/types.h> #include <linux/jump_label.h> +#include <uapi/linux/psci.h> #include <asm/kvm_asm.h> #include <asm/kvm_emulate.h> @@ -341,6 +342,18 @@ 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) && + vcpu_get_reg(vcpu, 0) == PSCI_0_2_FN_PSCI_VERSION) { + u64 val = PSCI_RET_NOT_SUPPORTED; + if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) + val = 2; + + vcpu_set_reg(vcpu, 0, val); + goto again; + } + if (static_branch_unlikely(&vgic_v2_cpuif_trap) && exit_code == ARM_EXCEPTION_TRAP) { bool valid; Patches currently in stable-queue which might be from marc.zyngier(a)arm.com are queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

7 years, 4 months

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Patch "[Variant 2/Spectre-v2] arm64: KVM: Increment PC after handling an SMC trap" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 2/Spectre-v2] arm64: KVM: Increment PC after handling an SMC trap to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kvm-increment-pc-after-handling-an-smc-trap.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Marc Zyngier <marc.zyngier(a)arm.com> Date: Tue, 6 Feb 2018 17:56:07 +0000 Subject: [Variant 2/Spectre-v2] arm64: KVM: Increment PC after handling an SMC trap From: Marc Zyngier <marc.zyngier(a)arm.com> Commit f5115e8869e1 upstream. When handling an SMC trap, the "preferred return address" is set to that of the SMC, and not the next PC (which is a departure from the behaviour of an SMC that isn't trapped). Increment PC in the handler, as the guest is otherwise forever stuck... Cc: stable(a)vger.kernel.org Fixes: acfb3b883f6d ("arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls") Reviewed-by: Christoffer Dall <christoffer.dall(a)linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel(a)linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier(a)arm.com> Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Signed-off-by: Will Deacon <will.deacon(a)arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm64/kvm/handle_exit.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -54,7 +54,16 @@ static int handle_hvc(struct kvm_vcpu *v static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) { + /* + * "If an SMC instruction executed at Non-secure EL1 is + * trapped to EL2 because HCR_EL2.TSC is 1, the exception is a + * Trap exception, not a Secure Monitor Call exception [...]" + * + * We need to advance the PC after the trap, as it would + * otherwise return to the same address... + */ vcpu_set_reg(vcpu, 0, ~0UL); + kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); return 1; } Patches currently in stable-queue which might be from marc.zyngier(a)arm.com are queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

7 years, 4 months

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Patch "[Variant 2/Spectre-v2] arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 2/Spectre-v2] arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Marc Zyngier <marc.zyngier(a)arm.com> Date: Tue, 6 Feb 2018 17:56:15 +0000 Subject: [Variant 2/Spectre-v2] arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling From: Marc Zyngier <marc.zyngier(a)arm.com> Commit f72af90c3783 upstream. We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible. So let's intercept it as early as we can by testing for the function call number as soon as we've identified a HVC call coming from the guest. Tested-by: Ard Biesheuvel <ard.biesheuvel(a)linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall(a)linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier(a)arm.com> Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Signed-off-by: Will Deacon <will.deacon(a)arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm64/kvm/hyp/hyp-entry.S | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -15,6 +15,7 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/arm-smccc.h> #include <linux/linkage.h> #include <asm/alternative.h> @@ -64,10 +65,11 @@ alternative_endif lsr x0, x1, #ESR_ELx_EC_SHIFT cmp x0, #ESR_ELx_EC_HVC64 + ccmp x0, #ESR_ELx_EC_HVC32, #4, ne b.ne el1_trap - mrs x1, vttbr_el2 // If vttbr is valid, the 64bit guest - cbnz x1, el1_trap // called HVC + mrs x1, vttbr_el2 // If vttbr is valid, the guest + cbnz x1, el1_hvc_guest // called HVC /* Here, we're pretty sure the host called HVC. */ ldp x0, x1, [sp], #16 @@ -100,6 +102,20 @@ alternative_endif eret +el1_hvc_guest: + /* + * Fastest possible path for ARM_SMCCC_ARCH_WORKAROUND_1. + * The workaround has already been applied on the host, + * so let's quickly get back to the guest. We don't bother + * restoring x1, as it can be clobbered anyway. + */ + ldr x1, [sp] // Guest's x0 + eor w1, w1, #ARM_SMCCC_ARCH_WORKAROUND_1 + cbnz w1, el1_trap + mov x0, x1 + add sp, sp, #16 + eret + el1_trap: /* * x0: ESR_EC Patches currently in stable-queue which might be from marc.zyngier(a)arm.com are queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

7 years, 4 months

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Patch "[Variant 3/Meltdown] arm64: kpti: Make use of nG dependent on arm64_kernel_unmapped_at_el0()" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 3/Meltdown] arm64: kpti: Make use of nG dependent on arm64_kernel_unmapped_at_el0() to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kpti-make-use-of-ng-dependent-on-arm64_kernel_unmapped_at_el0.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Will Deacon <will.deacon(a)arm.com> Date: Mon, 29 Jan 2018 11:59:53 +0000 Subject: [Variant 3/Meltdown] arm64: kpti: Make use of nG dependent on arm64_kernel_unmapped_at_el0() From: Will Deacon <will.deacon(a)arm.com> Commit 41acec624087 upstream. To allow systems which do not require kpti to continue running with global kernel mappings (which appears to be a requirement for Cavium ThunderX due to a CPU erratum), make the use of nG in the kernel page tables dependent on arm64_kernel_unmapped_at_el0(), which is resolved at runtime. Signed-off-by: Will Deacon <will.deacon(a)arm.com> Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm64/include/asm/kernel-pgtable.h | 12 ++---------- arch/arm64/include/asm/pgtable-prot.h | 30 ++++++++++++++---------------- 2 files changed, 16 insertions(+), 26 deletions(-) --- a/arch/arm64/include/asm/kernel-pgtable.h +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -78,16 +78,8 @@ /* * Initial memory map attributes. */ -#define _SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) -#define _SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) - -#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 -#define SWAPPER_PTE_FLAGS (_SWAPPER_PTE_FLAGS | PTE_NG) -#define SWAPPER_PMD_FLAGS (_SWAPPER_PMD_FLAGS | PMD_SECT_NG) -#else -#define SWAPPER_PTE_FLAGS _SWAPPER_PTE_FLAGS -#define SWAPPER_PMD_FLAGS _SWAPPER_PMD_FLAGS -#endif +#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) +#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) #if ARM64_SWAPPER_USES_SECTION_MAPS #define SWAPPER_MM_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS) --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -37,13 +37,11 @@ #define _PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) #define _PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) -#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 -#define PROT_DEFAULT (_PROT_DEFAULT | PTE_NG) -#define PROT_SECT_DEFAULT (_PROT_SECT_DEFAULT | PMD_SECT_NG) -#else -#define PROT_DEFAULT _PROT_DEFAULT -#define PROT_SECT_DEFAULT _PROT_SECT_DEFAULT -#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ +#define PTE_MAYBE_NG (arm64_kernel_unmapped_at_el0() ? PTE_NG : 0) +#define PMD_MAYBE_NG (arm64_kernel_unmapped_at_el0() ? PMD_SECT_NG : 0) + +#define PROT_DEFAULT (_PROT_DEFAULT | PTE_MAYBE_NG) +#define PROT_SECT_DEFAULT (_PROT_SECT_DEFAULT | PMD_MAYBE_NG) #define PROT_DEVICE_nGnRnE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRnE)) #define PROT_DEVICE_nGnRE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRE)) @@ -55,22 +53,22 @@ #define PROT_SECT_NORMAL (PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL)) #define PROT_SECT_NORMAL_EXEC (PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL)) -#define _PAGE_DEFAULT (PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL)) -#define _HYP_PAGE_DEFAULT (_PAGE_DEFAULT & ~PTE_NG) +#define _PAGE_DEFAULT (_PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL)) +#define _HYP_PAGE_DEFAULT _PAGE_DEFAULT -#define PAGE_KERNEL __pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE) -#define PAGE_KERNEL_RO __pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_RDONLY) -#define PAGE_KERNEL_ROX __pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_RDONLY) -#define PAGE_KERNEL_EXEC __pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE) -#define PAGE_KERNEL_EXEC_CONT __pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_CONT) +#define PAGE_KERNEL __pgprot(PROT_NORMAL) +#define PAGE_KERNEL_RO __pgprot((PROT_NORMAL & ~PTE_WRITE) | PTE_RDONLY) +#define PAGE_KERNEL_ROX __pgprot((PROT_NORMAL & ~(PTE_WRITE | PTE_PXN)) | PTE_RDONLY) +#define PAGE_KERNEL_EXEC __pgprot(PROT_NORMAL & ~PTE_PXN) +#define PAGE_KERNEL_EXEC_CONT __pgprot((PROT_NORMAL & ~PTE_PXN) | PTE_CONT) #define PAGE_HYP __pgprot(_HYP_PAGE_DEFAULT | PTE_HYP | PTE_HYP_XN) #define PAGE_HYP_EXEC __pgprot(_HYP_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY) #define PAGE_HYP_RO __pgprot(_HYP_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY | PTE_HYP_XN) #define PAGE_HYP_DEVICE __pgprot(PROT_DEVICE_nGnRE | PTE_HYP) -#define PAGE_S2 __pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY) -#define PAGE_S2_DEVICE __pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_UXN) +#define PAGE_S2 __pgprot(_PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY) +#define PAGE_S2_DEVICE __pgprot(_PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_UXN) #define PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN) #define PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE) Patches currently in stable-queue which might be from will.deacon(a)arm.com are queue-4.15/arm64-make-user_ds-an-inclusive-limit.patch queue-4.15/arm64-mm-remove-pre_ttbr0_update_workaround-for-falkor-erratum-e1003.patch queue-4.15/arm64-uaccess-don-t-bother-eliding-access_ok-checks-in-__-get-put-_user.patch queue-4.15/arm64-cpufeature-pass-capability-structure-to-enable-callback.patch queue-4.15/arm64-uaccess-mask-__user-pointers-for-__arch_-clear-copy_-_user.patch queue-4.15/arm64-mm-add-arm64_kernel_unmapped_at_el0-helper.patch queue-4.15/arm64-entry-reword-comment-about-post_ttbr_update_workaround.patch queue-4.15/arm64-kaslr-put-kernel-vectors-address-in-separate-data-page.patch queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/arm64-turn-on-kpti-only-on-cpus-that-need-it.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-mm-permit-transitioning-from-global-to-non-global-without-bbm.patch queue-4.15/arm64-mm-allocate-asids-in-pairs.patch queue-4.15/arm64-tls-avoid-unconditional-zeroing-of-tpidrro_el0-for-native-tasks.patch queue-4.15/arm64-use-ret-instruction-for-exiting-the-trampoline.patch queue-4.15/arm64-futex-mask-__user-pointers-prior-to-dereference.patch queue-4.15/arm64-entry-explicitly-pass-exception-level-to-kernel_ventry-macro.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm64-kpti-make-use-of-ng-dependent-on-arm64_kernel_unmapped_at_el0.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-ensure-branch-through-syscall-table-is-bounded-under-speculation.patch queue-4.15/arm64-mm-use-non-global-mappings-for-kernel-space.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-entry-hook-up-entry-trampoline-to-exception-vectors.patch queue-4.15/arm64-branch-predictor-hardening-for-cavium-thunderx2.patch queue-4.15/arm64-uaccess-prevent-speculative-use-of-the-current-addr_limit.patch queue-4.15/arm64-use-pointer-masking-to-limit-uaccess-speculation.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm64-erratum-work-around-falkor-erratum-e1003-in-trampoline-code.patch queue-4.15/arm64-mm-fix-and-re-enable-arm64_sw_ttbr0_pan.patch queue-4.15/arm64-mm-invalidate-both-kernel-and-user-asids-when-performing-tlbi.patch queue-4.15/drivers-firmware-expose-psci_get_version-through-psci_ops-structure.patch queue-4.15/arm64-mm-rename-post_ttbr0_update_workaround.patch queue-4.15/arm64-mm-map-entry-trampoline-into-trampoline-and-kernel-page-tables.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kconfig-reword-unmap_kernel_at_el0-kconfig-entry.patch queue-4.15/arm64-mm-move-asid-from-ttbr0-to-ttbr1.patch queue-4.15/arm64-mm-introduce-ttbr_asid_mask-for-getting-at-the-asid-in-the-ttbr.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-take-into-account-id_aa64pfr0_el1.csv3.patch queue-4.15/arm64-cputype-add-missing-midr-values-for-cortex-a72-and-cortex-a75.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm64-barrier-add-csdb-macros-to-control-data-value-prediction.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/perf-arm_spe-fail-device-probe-when-arm64_kernel_unmapped_at_el0.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-falkor.patch queue-4.15/arm64-kconfig-add-config_unmap_kernel_at_el0.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-run-enable-method-for-errata-work-arounds-on-late-cpus.patch queue-4.15/arm64-mm-temporarily-disable-arm64_sw_ttbr0_pan.patch queue-4.15/arm64-entry-add-exception-trampoline-page-for-exceptions-from-el0.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-implement-array_index_mask_nospec.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm64-cpu_errata-add-kryo-to-falkor-1003-errata.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-entry-add-fake-cpu-feature-for-unmapping-the-kernel-at-el0.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-cputype-add-midr-values-for-cavium-thunderx2-cpus.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

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Patch "[Variant 3/Meltdown] arm64: kpti: Fix the interaction between ASID switching and software PAN" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 3/Meltdown] arm64: kpti: Fix the interaction between ASID switching and software PAN to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Catalin Marinas <catalin.marinas(a)arm.com> Date: Wed, 10 Jan 2018 13:18:30 +0000 Subject: [Variant 3/Meltdown] arm64: kpti: Fix the interaction between ASID switching and software PAN From: Catalin Marinas <catalin.marinas(a)arm.com> Commit 6b88a32c7af6 upstream. With ARM64_SW_TTBR0_PAN enabled, the exception entry code checks the active ASID to decide whether user access was enabled (non-zero ASID) when the exception was taken. On return from exception, if user access was previously disabled, it re-instates TTBR0_EL1 from the per-thread saved value (updated in switch_mm() or efi_set_pgd()). Commit 7655abb95386 ("arm64: mm: Move ASID from TTBR0 to TTBR1") makes a TTBR0_EL1 + ASID switching non-atomic. Subsequently, commit 27a921e75711 ("arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN") changes the __uaccess_ttbr0_disable() function and asm macro to first write the reserved TTBR0_EL1 followed by the ASID=0 update in TTBR1_EL1. If an exception occurs between these two, the exception return code will re-instate a valid TTBR0_EL1. Similar scenario can happen in cpu_switch_mm() between setting the reserved TTBR0_EL1 and the ASID update in cpu_do_switch_mm(). This patch reverts the entry.S check for ASID == 0 to TTBR0_EL1 and disables the interrupts around the TTBR0_EL1 and ASID switching code in __uaccess_ttbr0_disable(). It also ensures that, when returning from the EFI runtime services, efi_set_pgd() doesn't leave a non-zero ASID in TTBR1_EL1 by using uaccess_ttbr0_{enable,disable}. The accesses to current_thread_info()->ttbr0 are updated to use READ_ONCE/WRITE_ONCE. As a safety measure, __uaccess_ttbr0_enable() always masks out any existing non-zero ASID TTBR1_EL1 before writing in the new ASID. Fixes: 27a921e75711 ("arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN") Acked-by: Will Deacon <will.deacon(a)arm.com> Reported-by: Ard Biesheuvel <ard.biesheuvel(a)linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel(a)linaro.org> Reviewed-by: James Morse <james.morse(a)arm.com> Tested-by: James Morse <james.morse(a)arm.com> Co-developed-by: Marc Zyngier <marc.zyngier(a)arm.com> Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Signed-off-by: Will Deacon <will.deacon(a)arm.com> Conflicts: arch/arm64/include/asm/asm-uaccess.h arch/arm64/include/asm/uaccess.h Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm64/include/asm/asm-uaccess.h | 12 +++++++----- arch/arm64/include/asm/efi.h | 12 +++++++----- arch/arm64/include/asm/mmu_context.h | 3 ++- arch/arm64/include/asm/uaccess.h | 9 ++++++--- arch/arm64/kernel/entry.S | 2 +- arch/arm64/lib/clear_user.S | 2 +- arch/arm64/lib/copy_from_user.S | 2 +- arch/arm64/lib/copy_in_user.S | 2 +- arch/arm64/lib/copy_to_user.S | 2 +- arch/arm64/mm/cache.S | 2 +- arch/arm64/mm/proc.S | 3 +++ arch/arm64/xen/hypercall.S | 2 +- 12 files changed, 32 insertions(+), 21 deletions(-) --- a/arch/arm64/include/asm/asm-uaccess.h +++ b/arch/arm64/include/asm/asm-uaccess.h @@ -14,11 +14,11 @@ #ifdef CONFIG_ARM64_SW_TTBR0_PAN .macro __uaccess_ttbr0_disable, tmp1 mrs \tmp1, ttbr1_el1 // swapper_pg_dir + bic \tmp1, \tmp1, #TTBR_ASID_MASK add \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 isb sub \tmp1, \tmp1, #SWAPPER_DIR_SIZE - bic \tmp1, \tmp1, #TTBR_ASID_MASK msr ttbr1_el1, \tmp1 // set reserved ASID isb .endm @@ -35,9 +35,11 @@ isb .endm - .macro uaccess_ttbr0_disable, tmp1 + .macro uaccess_ttbr0_disable, tmp1, tmp2 alternative_if_not ARM64_HAS_PAN + save_and_disable_irq \tmp2 // avoid preemption __uaccess_ttbr0_disable \tmp1 + restore_irq \tmp2 alternative_else_nop_endif .endm @@ -49,7 +51,7 @@ alternative_if_not ARM64_HAS_PAN alternative_else_nop_endif .endm #else - .macro uaccess_ttbr0_disable, tmp1 + .macro uaccess_ttbr0_disable, tmp1, tmp2 .endm .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3 @@ -59,8 +61,8 @@ alternative_else_nop_endif /* * These macros are no-ops when UAO is present. */ - .macro uaccess_disable_not_uao, tmp1 - uaccess_ttbr0_disable \tmp1 + .macro uaccess_disable_not_uao, tmp1, tmp2 + uaccess_ttbr0_disable \tmp1, \tmp2 alternative_if ARM64_ALT_PAN_NOT_UAO SET_PSTATE_PAN(1) alternative_else_nop_endif --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -121,19 +121,21 @@ static inline void efi_set_pgd(struct mm if (mm != current->active_mm) { /* * Update the current thread's saved ttbr0 since it is - * restored as part of a return from exception. Set - * the hardware TTBR0_EL1 using cpu_switch_mm() - * directly to enable potential errata workarounds. + * restored as part of a return from exception. Enable + * access to the valid TTBR0_EL1 and invoke the errata + * workaround directly since there is no return from + * exception when invoking the EFI run-time services. */ update_saved_ttbr0(current, mm); - cpu_switch_mm(mm->pgd, mm); + uaccess_ttbr0_enable(); + post_ttbr_update_workaround(); } else { /* * Defer the switch to the current thread's TTBR0_EL1 * until uaccess_enable(). Restore the current * thread's saved ttbr0 corresponding to its active_mm */ - cpu_set_reserved_ttbr0(); + uaccess_ttbr0_disable(); update_saved_ttbr0(current, current->active_mm); } } --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -175,7 +175,7 @@ static inline void update_saved_ttbr0(st else ttbr = virt_to_phys(mm->pgd) | ASID(mm) << 48; - task_thread_info(tsk)->ttbr0 = ttbr; + WRITE_ONCE(task_thread_info(tsk)->ttbr0, ttbr); } #else static inline void update_saved_ttbr0(struct task_struct *tsk, @@ -230,6 +230,7 @@ switch_mm(struct mm_struct *prev, struct #define activate_mm(prev,next) switch_mm(prev, next, current) void verify_cpu_asid_bits(void); +void post_ttbr_update_workaround(void); #endif /* !__ASSEMBLY__ */ --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -105,16 +105,18 @@ static inline void set_fs(mm_segment_t f #ifdef CONFIG_ARM64_SW_TTBR0_PAN static inline void __uaccess_ttbr0_disable(void) { - unsigned long ttbr; + unsigned long flags, ttbr; + local_irq_save(flags); ttbr = read_sysreg(ttbr1_el1); + ttbr &= ~TTBR_ASID_MASK; /* reserved_ttbr0 placed at the end of swapper_pg_dir */ write_sysreg(ttbr + SWAPPER_DIR_SIZE, ttbr0_el1); isb(); /* Set reserved ASID */ - ttbr &= ~TTBR_ASID_MASK; write_sysreg(ttbr, ttbr1_el1); isb(); + local_irq_restore(flags); } static inline void __uaccess_ttbr0_enable(void) @@ -127,10 +129,11 @@ static inline void __uaccess_ttbr0_enabl * roll-over and an update of 'ttbr0'. */ local_irq_save(flags); - ttbr0 = current_thread_info()->ttbr0; + ttbr0 = READ_ONCE(current_thread_info()->ttbr0); /* Restore active ASID */ ttbr1 = read_sysreg(ttbr1_el1); + ttbr1 &= ~TTBR_ASID_MASK; /* safety measure */ ttbr1 |= ttbr0 & TTBR_ASID_MASK; write_sysreg(ttbr1, ttbr1_el1); isb(); --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -204,7 +204,7 @@ alternative_if ARM64_HAS_PAN alternative_else_nop_endif .if \el != 0 - mrs x21, ttbr1_el1 + mrs x21, ttbr0_el1 tst x21, #TTBR_ASID_MASK // Check for the reserved ASID orr x23, x23, #PSR_PAN_BIT // Set the emulated PAN in the saved SPSR b.eq 1f // TTBR0 access already disabled --- a/arch/arm64/lib/clear_user.S +++ b/arch/arm64/lib/clear_user.S @@ -50,7 +50,7 @@ uao_user_alternative 9f, strh, sttrh, wz b.mi 5f uao_user_alternative 9f, strb, sttrb, wzr, x0, 0 5: mov x0, #0 - uaccess_disable_not_uao x2 + uaccess_disable_not_uao x2, x3 ret ENDPROC(__clear_user) --- a/arch/arm64/lib/copy_from_user.S +++ b/arch/arm64/lib/copy_from_user.S @@ -67,7 +67,7 @@ ENTRY(__arch_copy_from_user) uaccess_enable_not_uao x3, x4, x5 add end, x0, x2 #include "copy_template.S" - uaccess_disable_not_uao x3 + uaccess_disable_not_uao x3, x4 mov x0, #0 // Nothing to copy ret ENDPROC(__arch_copy_from_user) --- a/arch/arm64/lib/copy_in_user.S +++ b/arch/arm64/lib/copy_in_user.S @@ -68,7 +68,7 @@ ENTRY(raw_copy_in_user) uaccess_enable_not_uao x3, x4, x5 add end, x0, x2 #include "copy_template.S" - uaccess_disable_not_uao x3 + uaccess_disable_not_uao x3, x4 mov x0, #0 ret ENDPROC(raw_copy_in_user) --- a/arch/arm64/lib/copy_to_user.S +++ b/arch/arm64/lib/copy_to_user.S @@ -66,7 +66,7 @@ ENTRY(__arch_copy_to_user) uaccess_enable_not_uao x3, x4, x5 add end, x0, x2 #include "copy_template.S" - uaccess_disable_not_uao x3 + uaccess_disable_not_uao x3, x4 mov x0, #0 ret ENDPROC(__arch_copy_to_user) --- a/arch/arm64/mm/cache.S +++ b/arch/arm64/mm/cache.S @@ -72,7 +72,7 @@ USER(9f, ic ivau, x4 ) // invalidate I isb mov x0, #0 1: - uaccess_ttbr0_disable x1 + uaccess_ttbr0_disable x1, x2 ret 9: mov x0, #-EFAULT --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -140,6 +140,9 @@ ENDPROC(cpu_do_resume) ENTRY(cpu_do_switch_mm) mrs x2, ttbr1_el1 mmid x1, x1 // get mm->context.id +#ifdef CONFIG_ARM64_SW_TTBR0_PAN + bfi x0, x1, #48, #16 // set the ASID field in TTBR0 +#endif bfi x2, x1, #48, #16 // set the ASID msr ttbr1_el1, x2 // in TTBR1 (since TCR.A1 is set) isb --- a/arch/arm64/xen/hypercall.S +++ b/arch/arm64/xen/hypercall.S @@ -107,6 +107,6 @@ ENTRY(privcmd_call) /* * Disable userspace access from kernel once the hyp call completed. */ - uaccess_ttbr0_disable x6 + uaccess_ttbr0_disable x6, x7 ret ENDPROC(privcmd_call); Patches currently in stable-queue which might be from catalin.marinas(a)arm.com are queue-4.15/arm64-make-user_ds-an-inclusive-limit.patch queue-4.15/arm64-uaccess-don-t-bother-eliding-access_ok-checks-in-__-get-put-_user.patch queue-4.15/arm64-cpufeature-pass-capability-structure-to-enable-callback.patch queue-4.15/arm64-uaccess-mask-__user-pointers-for-__arch_-clear-copy_-_user.patch queue-4.15/arm64-entry-reword-comment-about-post_ttbr_update_workaround.patch queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/arm64-turn-on-kpti-only-on-cpus-that-need-it.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-mm-permit-transitioning-from-global-to-non-global-without-bbm.patch queue-4.15/arm64-use-ret-instruction-for-exiting-the-trampoline.patch queue-4.15/arm64-futex-mask-__user-pointers-prior-to-dereference.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm64-kpti-make-use-of-ng-dependent-on-arm64_kernel_unmapped_at_el0.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-ensure-branch-through-syscall-table-is-bounded-under-speculation.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-branch-predictor-hardening-for-cavium-thunderx2.patch queue-4.15/arm64-uaccess-prevent-speculative-use-of-the-current-addr_limit.patch queue-4.15/arm64-use-pointer-masking-to-limit-uaccess-speculation.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/drivers-firmware-expose-psci_get_version-through-psci_ops-structure.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kconfig-reword-unmap_kernel_at_el0-kconfig-entry.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-take-into-account-id_aa64pfr0_el1.csv3.patch queue-4.15/arm64-cputype-add-missing-midr-values-for-cortex-a72-and-cortex-a75.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm64-barrier-add-csdb-macros-to-control-data-value-prediction.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-falkor.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-run-enable-method-for-errata-work-arounds-on-late-cpus.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-implement-array_index_mask_nospec.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm64-cpu_errata-add-kryo-to-falkor-1003-errata.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-cputype-add-midr-values-for-cavium-thunderx2-cpus.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

7 years, 4 months

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Patch "[Variant 2/Spectre-v2] arm64: Kill PSCI_GET_VERSION as a variant-2 workaround" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 2/Spectre-v2] arm64: Kill PSCI_GET_VERSION as a variant-2 workaround to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kill-psci_get_version-as-a-variant-2-workaround.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Marc Zyngier <marc.zyngier(a)arm.com> Date: Tue, 6 Feb 2018 17:56:21 +0000 Subject: [Variant 2/Spectre-v2] arm64: Kill PSCI_GET_VERSION as a variant-2 workaround From: Marc Zyngier <marc.zyngier(a)arm.com> Commit 3a0a397ff5ff 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(a)linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier(a)arm.com> Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Signed-off-by: Will Deacon <will.deacon(a)arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)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) ENTRY(__qcom_hyp_sanitize_link_stack_start) stp x29, x30, [sp, #-16]! --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -67,7 +67,6 @@ 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 __qcom_hyp_sanitize_link_stack_start[]; extern char __qcom_hyp_sanitize_link_stack_end[]; extern char __smccc_workaround_1_smc_start[]; @@ -116,8 +115,6 @@ 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 __qcom_hyp_sanitize_link_stack_start NULL #define __qcom_hyp_sanitize_link_stack_end NULL #define __smccc_workaround_1_smc_start NULL @@ -164,24 +161,25 @@ 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; @@ -191,35 +189,18 @@ 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; } @@ -399,22 +380,22 @@ 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, @@ -428,12 +409,12 @@ const struct arm64_cpu_capabilities arm6 { .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 @@ -344,20 +344,6 @@ 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; Patches currently in stable-queue which might be from marc.zyngier(a)arm.com are queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

7 years, 4 months

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Patch "[Variant 3/Meltdown] arm64: kpti: Add ->enable callback to remap swapper using nG mappings" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 3/Meltdown] arm64: kpti: Add ->enable callback to remap swapper using nG mappings to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Will Deacon <will.deacon(a)arm.com> Date: Tue, 6 Feb 2018 22:22:50 +0000 Subject: [Variant 3/Meltdown] arm64: kpti: Add ->enable callback to remap swapper using nG mappings From: Will Deacon <will.deacon(a)arm.com> Commit f992b4dfd58b upstream. Defaulting to global mappings for kernel space is generally good for performance and appears to be necessary for Cavium ThunderX. If we subsequently decide that we need to enable kpti, then we need to rewrite our existing page table entries to be non-global. This is fiddly, and made worse by the possible use of contiguous mappings, which require a strict break-before-make sequence. Since the enable callback runs on each online CPU from stop_machine context, we can have all CPUs enter the idmap, where secondaries can wait for the primary CPU to rewrite swapper with its MMU off. It's all fairly horrible, but at least it only runs once. Tested-by: Marc Zyngier <marc.zyngier(a)arm.com> Reviewed-by: Marc Zyngier <marc.zyngier(a)arm.com> Signed-off-by: Will Deacon <will.deacon(a)arm.com> Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Conflicts: arch/arm64/mm/proc.S Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm64/include/asm/assembler.h | 4 arch/arm64/kernel/cpufeature.c | 25 ++++ arch/arm64/mm/proc.S | 202 +++++++++++++++++++++++++++++++++++-- 3 files changed, 224 insertions(+), 7 deletions(-) --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -489,6 +489,10 @@ alternative_else_nop_endif #endif .endm + .macro pte_to_phys, phys, pte + and \phys, \pte, #(((1 << (48 - PAGE_SHIFT)) - 1) << PAGE_SHIFT) + .endm + /** * Errata workaround prior to disable MMU. Insert an ISB immediately prior * to executing the MSR that will change SCTLR_ELn[M] from a value of 1 to 0. --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -878,6 +878,30 @@ static bool unmap_kernel_at_el0(const st ID_AA64PFR0_CSV3_SHIFT); } +static int kpti_install_ng_mappings(void *__unused) +{ + typedef void (kpti_remap_fn)(int, int, phys_addr_t); + extern kpti_remap_fn idmap_kpti_install_ng_mappings; + kpti_remap_fn *remap_fn; + + static bool kpti_applied = false; + int cpu = smp_processor_id(); + + if (kpti_applied) + return 0; + + remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings); + + cpu_install_idmap(); + remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir)); + cpu_uninstall_idmap(); + + if (!cpu) + kpti_applied = true; + + return 0; +} + static int __init parse_kpti(char *str) { bool enabled; @@ -984,6 +1008,7 @@ static const struct arm64_cpu_capabiliti .capability = ARM64_UNMAP_KERNEL_AT_EL0, .def_scope = SCOPE_SYSTEM, .matches = unmap_kernel_at_el0, + .enable = kpti_install_ng_mappings, }, #endif { --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -153,6 +153,16 @@ ENTRY(cpu_do_switch_mm) ENDPROC(cpu_do_switch_mm) .pushsection ".idmap.text", "ax" + +.macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2 + adrp \tmp1, empty_zero_page + msr ttbr1_el1, \tmp2 + isb + tlbi vmalle1 + dsb nsh + isb +.endm + /* * void idmap_cpu_replace_ttbr1(phys_addr_t new_pgd) * @@ -162,13 +172,7 @@ ENDPROC(cpu_do_switch_mm) ENTRY(idmap_cpu_replace_ttbr1) save_and_disable_daif flags=x2 - adrp x1, empty_zero_page - msr ttbr1_el1, x1 - isb - - tlbi vmalle1 - dsb nsh - isb + __idmap_cpu_set_reserved_ttbr1 x1, x3 msr ttbr1_el1, x0 isb @@ -179,6 +183,190 @@ ENTRY(idmap_cpu_replace_ttbr1) ENDPROC(idmap_cpu_replace_ttbr1) .popsection +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + .pushsection ".idmap.text", "ax" + + .macro __idmap_kpti_get_pgtable_ent, type + dc cvac, cur_\()\type\()p // Ensure any existing dirty + dmb sy // lines are written back before + ldr \type, [cur_\()\type\()p] // loading the entry + tbz \type, #0, next_\()\type // Skip invalid entries + .endm + + .macro __idmap_kpti_put_pgtable_ent_ng, type + orr \type, \type, #PTE_NG // Same bit for blocks and pages + str \type, [cur_\()\type\()p] // Update the entry and ensure it + dc civac, cur_\()\type\()p // is visible to all CPUs. + .endm + +/* + * void __kpti_install_ng_mappings(int cpu, int num_cpus, phys_addr_t swapper) + * + * Called exactly once from stop_machine context by each CPU found during boot. + */ +__idmap_kpti_flag: + .long 1 +ENTRY(idmap_kpti_install_ng_mappings) + cpu .req w0 + num_cpus .req w1 + swapper_pa .req x2 + swapper_ttb .req x3 + flag_ptr .req x4 + cur_pgdp .req x5 + end_pgdp .req x6 + pgd .req x7 + cur_pudp .req x8 + end_pudp .req x9 + pud .req x10 + cur_pmdp .req x11 + end_pmdp .req x12 + pmd .req x13 + cur_ptep .req x14 + end_ptep .req x15 + pte .req x16 + + mrs swapper_ttb, ttbr1_el1 + adr flag_ptr, __idmap_kpti_flag + + cbnz cpu, __idmap_kpti_secondary + + /* We're the boot CPU. Wait for the others to catch up */ + sevl +1: wfe + ldaxr w18, [flag_ptr] + eor w18, w18, num_cpus + cbnz w18, 1b + + /* We need to walk swapper, so turn off the MMU. */ + pre_disable_mmu_workaround + mrs x18, sctlr_el1 + bic x18, x18, #SCTLR_ELx_M + msr sctlr_el1, x18 + isb + + /* Everybody is enjoying the idmap, so we can rewrite swapper. */ + /* PGD */ + mov cur_pgdp, swapper_pa + add end_pgdp, cur_pgdp, #(PTRS_PER_PGD * 8) +do_pgd: __idmap_kpti_get_pgtable_ent pgd + tbnz pgd, #1, walk_puds + __idmap_kpti_put_pgtable_ent_ng pgd +next_pgd: + add cur_pgdp, cur_pgdp, #8 + cmp cur_pgdp, end_pgdp + b.ne do_pgd + + /* Publish the updated tables and nuke all the TLBs */ + dsb sy + tlbi vmalle1is + dsb ish + isb + + /* We're done: fire up the MMU again */ + mrs x18, sctlr_el1 + orr x18, x18, #SCTLR_ELx_M + msr sctlr_el1, x18 + isb + + /* Set the flag to zero to indicate that we're all done */ + str wzr, [flag_ptr] + ret + + /* PUD */ +walk_puds: + .if CONFIG_PGTABLE_LEVELS > 3 + pte_to_phys cur_pudp, pgd + add end_pudp, cur_pudp, #(PTRS_PER_PUD * 8) +do_pud: __idmap_kpti_get_pgtable_ent pud + tbnz pud, #1, walk_pmds + __idmap_kpti_put_pgtable_ent_ng pud +next_pud: + add cur_pudp, cur_pudp, 8 + cmp cur_pudp, end_pudp + b.ne do_pud + b next_pgd + .else /* CONFIG_PGTABLE_LEVELS <= 3 */ + mov pud, pgd + b walk_pmds +next_pud: + b next_pgd + .endif + + /* PMD */ +walk_pmds: + .if CONFIG_PGTABLE_LEVELS > 2 + pte_to_phys cur_pmdp, pud + add end_pmdp, cur_pmdp, #(PTRS_PER_PMD * 8) +do_pmd: __idmap_kpti_get_pgtable_ent pmd + tbnz pmd, #1, walk_ptes + __idmap_kpti_put_pgtable_ent_ng pmd +next_pmd: + add cur_pmdp, cur_pmdp, #8 + cmp cur_pmdp, end_pmdp + b.ne do_pmd + b next_pud + .else /* CONFIG_PGTABLE_LEVELS <= 2 */ + mov pmd, pud + b walk_ptes +next_pmd: + b next_pud + .endif + + /* PTE */ +walk_ptes: + pte_to_phys cur_ptep, pmd + add end_ptep, cur_ptep, #(PTRS_PER_PTE * 8) +do_pte: __idmap_kpti_get_pgtable_ent pte + __idmap_kpti_put_pgtable_ent_ng pte +next_pte: + add cur_ptep, cur_ptep, #8 + cmp cur_ptep, end_ptep + b.ne do_pte + b next_pmd + + /* Secondary CPUs end up here */ +__idmap_kpti_secondary: + /* Uninstall swapper before surgery begins */ + __idmap_cpu_set_reserved_ttbr1 x18, x17 + + /* Increment the flag to let the boot CPU we're ready */ +1: ldxr w18, [flag_ptr] + add w18, w18, #1 + stxr w17, w18, [flag_ptr] + cbnz w17, 1b + + /* Wait for the boot CPU to finish messing around with swapper */ + sevl +1: wfe + ldxr w18, [flag_ptr] + cbnz w18, 1b + + /* All done, act like nothing happened */ + msr ttbr1_el1, swapper_ttb + isb + ret + + .unreq cpu + .unreq num_cpus + .unreq swapper_pa + .unreq swapper_ttb + .unreq flag_ptr + .unreq cur_pgdp + .unreq end_pgdp + .unreq pgd + .unreq cur_pudp + .unreq end_pudp + .unreq pud + .unreq cur_pmdp + .unreq end_pmdp + .unreq pmd + .unreq cur_ptep + .unreq end_ptep + .unreq pte +ENDPROC(idmap_kpti_install_ng_mappings) + .popsection +#endif + /* * __cpu_setup * Patches currently in stable-queue which might be from will.deacon(a)arm.com are queue-4.15/arm64-make-user_ds-an-inclusive-limit.patch queue-4.15/arm64-mm-remove-pre_ttbr0_update_workaround-for-falkor-erratum-e1003.patch queue-4.15/arm64-uaccess-don-t-bother-eliding-access_ok-checks-in-__-get-put-_user.patch queue-4.15/arm64-cpufeature-pass-capability-structure-to-enable-callback.patch queue-4.15/arm64-uaccess-mask-__user-pointers-for-__arch_-clear-copy_-_user.patch queue-4.15/arm64-mm-add-arm64_kernel_unmapped_at_el0-helper.patch queue-4.15/arm64-entry-reword-comment-about-post_ttbr_update_workaround.patch queue-4.15/arm64-kaslr-put-kernel-vectors-address-in-separate-data-page.patch queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/arm64-turn-on-kpti-only-on-cpus-that-need-it.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-mm-permit-transitioning-from-global-to-non-global-without-bbm.patch queue-4.15/arm64-mm-allocate-asids-in-pairs.patch queue-4.15/arm64-tls-avoid-unconditional-zeroing-of-tpidrro_el0-for-native-tasks.patch queue-4.15/arm64-use-ret-instruction-for-exiting-the-trampoline.patch queue-4.15/arm64-futex-mask-__user-pointers-prior-to-dereference.patch queue-4.15/arm64-entry-explicitly-pass-exception-level-to-kernel_ventry-macro.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm64-kpti-make-use-of-ng-dependent-on-arm64_kernel_unmapped_at_el0.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-ensure-branch-through-syscall-table-is-bounded-under-speculation.patch queue-4.15/arm64-mm-use-non-global-mappings-for-kernel-space.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-entry-hook-up-entry-trampoline-to-exception-vectors.patch queue-4.15/arm64-branch-predictor-hardening-for-cavium-thunderx2.patch queue-4.15/arm64-uaccess-prevent-speculative-use-of-the-current-addr_limit.patch queue-4.15/arm64-use-pointer-masking-to-limit-uaccess-speculation.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm64-erratum-work-around-falkor-erratum-e1003-in-trampoline-code.patch queue-4.15/arm64-mm-fix-and-re-enable-arm64_sw_ttbr0_pan.patch queue-4.15/arm64-mm-invalidate-both-kernel-and-user-asids-when-performing-tlbi.patch queue-4.15/drivers-firmware-expose-psci_get_version-through-psci_ops-structure.patch queue-4.15/arm64-mm-rename-post_ttbr0_update_workaround.patch queue-4.15/arm64-mm-map-entry-trampoline-into-trampoline-and-kernel-page-tables.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kconfig-reword-unmap_kernel_at_el0-kconfig-entry.patch queue-4.15/arm64-mm-move-asid-from-ttbr0-to-ttbr1.patch queue-4.15/arm64-mm-introduce-ttbr_asid_mask-for-getting-at-the-asid-in-the-ttbr.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-take-into-account-id_aa64pfr0_el1.csv3.patch queue-4.15/arm64-cputype-add-missing-midr-values-for-cortex-a72-and-cortex-a75.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm64-barrier-add-csdb-macros-to-control-data-value-prediction.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/perf-arm_spe-fail-device-probe-when-arm64_kernel_unmapped_at_el0.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-falkor.patch queue-4.15/arm64-kconfig-add-config_unmap_kernel_at_el0.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-run-enable-method-for-errata-work-arounds-on-late-cpus.patch queue-4.15/arm64-mm-temporarily-disable-arm64_sw_ttbr0_pan.patch queue-4.15/arm64-entry-add-exception-trampoline-page-for-exceptions-from-el0.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-implement-array_index_mask_nospec.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm64-cpu_errata-add-kryo-to-falkor-1003-errata.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-entry-add-fake-cpu-feature-for-unmapping-the-kernel-at-el0.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-cputype-add-midr-values-for-cavium-thunderx2-cpus.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

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Patch "[Variant 3/Meltdown] arm64: Kconfig: Add CONFIG_UNMAP_KERNEL_AT_EL0" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 3/Meltdown] arm64: Kconfig: Add CONFIG_UNMAP_KERNEL_AT_EL0 to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kconfig-add-config_unmap_kernel_at_el0.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Will Deacon <will.deacon(a)arm.com> Date: Tue, 14 Nov 2017 14:41:01 +0000 Subject: [Variant 3/Meltdown] arm64: Kconfig: Add CONFIG_UNMAP_KERNEL_AT_EL0 From: Will Deacon <will.deacon(a)arm.com> Commit 084eb77cd3a8 upstream. Add a Kconfig entry to control use of the entry trampoline, which allows us to unmap the kernel whilst running in userspace and improve the robustness of KASLR. Reviewed-by: Mark Rutland <mark.rutland(a)arm.com> Tested-by: Laura Abbott <labbott(a)redhat.com> Tested-by: Shanker Donthineni <shankerd(a)codeaurora.org> Signed-off-by: Will Deacon <will.deacon(a)arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm64/Kconfig | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -843,6 +843,19 @@ config FORCE_MAX_ZONEORDER However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 4M allocations matching the default size used by generic code. +config UNMAP_KERNEL_AT_EL0 + bool "Unmap kernel when running in userspace (aka \"KAISER\")" + default y + help + Some attacks against KASLR make use of the timing difference between + a permission fault which could arise from a page table entry that is + present in the TLB, and a translation fault which always requires a + page table walk. This option defends against these attacks by unmapping + the kernel whilst running in userspace, therefore forcing translation + faults for all of kernel space. + + If unsure, say Y. + menuconfig ARMV8_DEPRECATED bool "Emulate deprecated/obsolete ARMv8 instructions" depends on COMPAT Patches currently in stable-queue which might be from will.deacon(a)arm.com are queue-4.15/arm64-make-user_ds-an-inclusive-limit.patch queue-4.15/arm64-mm-remove-pre_ttbr0_update_workaround-for-falkor-erratum-e1003.patch queue-4.15/arm64-uaccess-don-t-bother-eliding-access_ok-checks-in-__-get-put-_user.patch queue-4.15/arm64-cpufeature-pass-capability-structure-to-enable-callback.patch queue-4.15/arm64-uaccess-mask-__user-pointers-for-__arch_-clear-copy_-_user.patch queue-4.15/arm64-mm-add-arm64_kernel_unmapped_at_el0-helper.patch queue-4.15/arm64-entry-reword-comment-about-post_ttbr_update_workaround.patch queue-4.15/arm64-kaslr-put-kernel-vectors-address-in-separate-data-page.patch queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/arm64-turn-on-kpti-only-on-cpus-that-need-it.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-mm-permit-transitioning-from-global-to-non-global-without-bbm.patch queue-4.15/arm64-mm-allocate-asids-in-pairs.patch queue-4.15/arm64-tls-avoid-unconditional-zeroing-of-tpidrro_el0-for-native-tasks.patch queue-4.15/arm64-use-ret-instruction-for-exiting-the-trampoline.patch queue-4.15/arm64-futex-mask-__user-pointers-prior-to-dereference.patch queue-4.15/arm64-entry-explicitly-pass-exception-level-to-kernel_ventry-macro.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm64-kpti-make-use-of-ng-dependent-on-arm64_kernel_unmapped_at_el0.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-ensure-branch-through-syscall-table-is-bounded-under-speculation.patch queue-4.15/arm64-mm-use-non-global-mappings-for-kernel-space.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-entry-hook-up-entry-trampoline-to-exception-vectors.patch queue-4.15/arm64-branch-predictor-hardening-for-cavium-thunderx2.patch queue-4.15/arm64-uaccess-prevent-speculative-use-of-the-current-addr_limit.patch queue-4.15/arm64-use-pointer-masking-to-limit-uaccess-speculation.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm64-erratum-work-around-falkor-erratum-e1003-in-trampoline-code.patch queue-4.15/arm64-mm-fix-and-re-enable-arm64_sw_ttbr0_pan.patch queue-4.15/arm64-mm-invalidate-both-kernel-and-user-asids-when-performing-tlbi.patch queue-4.15/drivers-firmware-expose-psci_get_version-through-psci_ops-structure.patch queue-4.15/arm64-mm-rename-post_ttbr0_update_workaround.patch queue-4.15/arm64-mm-map-entry-trampoline-into-trampoline-and-kernel-page-tables.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kconfig-reword-unmap_kernel_at_el0-kconfig-entry.patch queue-4.15/arm64-mm-move-asid-from-ttbr0-to-ttbr1.patch queue-4.15/arm64-mm-introduce-ttbr_asid_mask-for-getting-at-the-asid-in-the-ttbr.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-take-into-account-id_aa64pfr0_el1.csv3.patch queue-4.15/arm64-cputype-add-missing-midr-values-for-cortex-a72-and-cortex-a75.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm64-barrier-add-csdb-macros-to-control-data-value-prediction.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/perf-arm_spe-fail-device-probe-when-arm64_kernel_unmapped_at_el0.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-falkor.patch queue-4.15/arm64-kconfig-add-config_unmap_kernel_at_el0.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-run-enable-method-for-errata-work-arounds-on-late-cpus.patch queue-4.15/arm64-mm-temporarily-disable-arm64_sw_ttbr0_pan.patch queue-4.15/arm64-entry-add-exception-trampoline-page-for-exceptions-from-el0.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-implement-array_index_mask_nospec.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm64-cpu_errata-add-kryo-to-falkor-1003-errata.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-entry-add-fake-cpu-feature-for-unmapping-the-kernel-at-el0.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-cputype-add-midr-values-for-cavium-thunderx2-cpus.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

7 years, 4 months

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Patch "[Variant 3/Meltdown] arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entry" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled [Variant 3/Meltdown] arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entry to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: arm64-kconfig-reword-unmap_kernel_at_el0-kconfig-entry.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Feb 13 17:25:10 CET 2018 From: Will Deacon <will.deacon(a)arm.com> Date: Tue, 14 Nov 2017 16:19:39 +0000 Subject: [Variant 3/Meltdown] arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entry From: Will Deacon <will.deacon(a)arm.com> Commit 0617052ddde3 upstream. Although CONFIG_UNMAP_KERNEL_AT_EL0 does make KASLR more robust, it's actually more useful as a mitigation against speculation attacks that can leak arbitrary kernel data to userspace through speculation. Reword the Kconfig help message to reflect this, and make the option depend on EXPERT so that it is on by default for the majority of users. Signed-off-by: Will Deacon <will.deacon(a)arm.com> Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/arm64/Kconfig | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -844,15 +844,14 @@ config FORCE_MAX_ZONEORDER 4M allocations matching the default size used by generic code. config UNMAP_KERNEL_AT_EL0 - bool "Unmap kernel when running in userspace (aka \"KAISER\")" + bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT default y help - Some attacks against KASLR make use of the timing difference between - a permission fault which could arise from a page table entry that is - present in the TLB, and a translation fault which always requires a - page table walk. This option defends against these attacks by unmapping - the kernel whilst running in userspace, therefore forcing translation - faults for all of kernel space. + Speculation attacks against some high-performance processors can + be used to bypass MMU permission checks and leak kernel data to + userspace. This can be defended against by unmapping the kernel + when running in userspace, mapping it back in on exception entry + via a trampoline page in the vector table. If unsure, say Y. Patches currently in stable-queue which might be from will.deacon(a)arm.com are queue-4.15/arm64-make-user_ds-an-inclusive-limit.patch queue-4.15/arm64-mm-remove-pre_ttbr0_update_workaround-for-falkor-erratum-e1003.patch queue-4.15/arm64-uaccess-don-t-bother-eliding-access_ok-checks-in-__-get-put-_user.patch queue-4.15/arm64-cpufeature-pass-capability-structure-to-enable-callback.patch queue-4.15/arm64-uaccess-mask-__user-pointers-for-__arch_-clear-copy_-_user.patch queue-4.15/arm64-mm-add-arm64_kernel_unmapped_at_el0-helper.patch queue-4.15/arm64-entry-reword-comment-about-post_ttbr_update_workaround.patch queue-4.15/arm64-kaslr-put-kernel-vectors-address-in-separate-data-page.patch queue-4.15/arm-arm64-smccc-make-function-identifiers-an-unsigned-quantity.patch queue-4.15/arm64-move-bp-hardening-to-check_and_switch_context.patch queue-4.15/arm-arm64-kvm-advertise-smccc-v1.1.patch queue-4.15/arm64-move-post_ttbr_update_workaround-to-c-code.patch queue-4.15/arm64-turn-on-kpti-only-on-cpus-that-need-it.patch queue-4.15/firmware-psci-expose-psci-conduit.patch queue-4.15/arm64-force-kpti-to-be-disabled-on-cavium-thunderx.patch queue-4.15/arm64-entry-apply-bp-hardening-for-high-priority-synchronous-exceptions.patch queue-4.15/arm64-kpti-fix-the-interaction-between-asid-switching-and-software-pan.patch queue-4.15/firmware-psci-expose-smccc-version-through-psci_ops.patch queue-4.15/arm64-mm-permit-transitioning-from-global-to-non-global-without-bbm.patch queue-4.15/arm64-mm-allocate-asids-in-pairs.patch queue-4.15/arm64-tls-avoid-unconditional-zeroing-of-tpidrro_el0-for-native-tasks.patch queue-4.15/arm64-use-ret-instruction-for-exiting-the-trampoline.patch queue-4.15/arm64-futex-mask-__user-pointers-prior-to-dereference.patch queue-4.15/arm64-entry-explicitly-pass-exception-level-to-kernel_ventry-macro.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-affected-cortex-a-cpus.patch queue-4.15/arm64-kpti-make-use-of-ng-dependent-on-arm64_kernel_unmapped_at_el0.patch queue-4.15/arm-arm64-kvm-add-psci_version-helper.patch queue-4.15/arm64-kill-psci_get_version-as-a-variant-2-workaround.patch queue-4.15/arm64-entry-ensure-branch-through-syscall-table-is-bounded-under-speculation.patch queue-4.15/arm64-mm-use-non-global-mappings-for-kernel-space.patch queue-4.15/arm64-entry-apply-bp-hardening-for-suspicious-interrupts-from-el0.patch queue-4.15/arm64-capabilities-handle-duplicate-entries-for-a-capability.patch queue-4.15/arm64-entry-hook-up-entry-trampoline-to-exception-vectors.patch queue-4.15/arm64-branch-predictor-hardening-for-cavium-thunderx2.patch queue-4.15/arm64-uaccess-prevent-speculative-use-of-the-current-addr_limit.patch queue-4.15/arm64-use-pointer-masking-to-limit-uaccess-speculation.patch queue-4.15/arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm64-erratum-work-around-falkor-erratum-e1003-in-trampoline-code.patch queue-4.15/arm64-mm-fix-and-re-enable-arm64_sw_ttbr0_pan.patch queue-4.15/arm64-mm-invalidate-both-kernel-and-user-asids-when-performing-tlbi.patch queue-4.15/drivers-firmware-expose-psci_get_version-through-psci_ops-structure.patch queue-4.15/arm64-mm-rename-post_ttbr0_update_workaround.patch queue-4.15/arm64-mm-map-entry-trampoline-into-trampoline-and-kernel-page-tables.patch queue-4.15/arm-arm64-kvm-turn-kvm_psci_version-into-a-static-inline.patch queue-4.15/arm-arm64-kvm-implement-psci-1.0-support.patch queue-4.15/arm64-kconfig-reword-unmap_kernel_at_el0-kconfig-entry.patch queue-4.15/arm64-mm-move-asid-from-ttbr0-to-ttbr1.patch queue-4.15/arm64-mm-introduce-ttbr_asid_mask-for-getting-at-the-asid-in-the-ttbr.patch queue-4.15/arm64-kvm-add-smccc_arch_workaround_1-fast-handling.patch queue-4.15/arm64-take-into-account-id_aa64pfr0_el1.csv3.patch queue-4.15/arm64-cputype-add-missing-midr-values-for-cortex-a72-and-cortex-a75.patch queue-4.15/arm64-kvm-report-smccc_arch_workaround_1-bp-hardening-support.patch queue-4.15/arm64-barrier-add-csdb-macros-to-control-data-value-prediction.patch queue-4.15/arm-arm64-smccc-implement-smccc-v1.1-inline-primitive.patch queue-4.15/perf-arm_spe-fail-device-probe-when-arm64_kernel_unmapped_at_el0.patch queue-4.15/arm64-implement-branch-predictor-hardening-for-falkor.patch queue-4.15/arm64-kconfig-add-config_unmap_kernel_at_el0.patch queue-4.15/arm64-idmap-use-awx-flags-for-.idmap.text-.pushsection-directives.patch queue-4.15/arm64-run-enable-method-for-errata-work-arounds-on-late-cpus.patch queue-4.15/arm64-mm-temporarily-disable-arm64_sw_ttbr0_pan.patch queue-4.15/arm64-entry-add-exception-trampoline-page-for-exceptions-from-el0.patch queue-4.15/arm64-kvm-make-psci_version-a-fast-path.patch queue-4.15/arm64-cpufeature-__this_cpu_has_cap-shouldn-t-stop-early.patch queue-4.15/arm64-implement-array_index_mask_nospec.patch queue-4.15/arm64-kpti-add-enable-callback-to-remap-swapper-using-ng-mappings.patch queue-4.15/arm-arm64-kvm-consolidate-the-psci-include-files.patch queue-4.15/arm64-add-skeleton-to-harden-the-branch-predictor-against-aliasing-attacks.patch queue-4.15/arm64-cpu_errata-add-kryo-to-falkor-1003-errata.patch queue-4.15/arm-arm64-kvm-add-smccc-accessors-to-psci-code.patch queue-4.15/arm64-entry-add-fake-cpu-feature-for-unmapping-the-kernel-at-el0.patch queue-4.15/arm64-kvm-use-per-cpu-vector-when-bp-hardening-is-enabled.patch queue-4.15/arm64-cputype-add-midr-values-for-cavium-thunderx2-cpus.patch queue-4.15/arm64-kvm-increment-pc-after-handling-an-smc-trap.patch

7 years, 4 months

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