Patch "[Variant 2/Spectre-v2] arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

[Variant 2/Spectre-v2] arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support

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=summary

The filename of the patch is:
arm64-add-arm_smccc_arch_workaround_1-bp-hardening-support.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 <[email protected]> know about it.

From: Marc Zyngier <[email protected]>
Date: Tue, 6 Feb 2018 17:56:20 +0000
Subject: [Variant 2/Spectre-v2] arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support

From: Marc Zyngier <[email protected]>

Commit b092201e0020 upstream.

Add the detection and runtime code for ARM_SMCCC_ARCH_WORKAROUND_1. It is lovely. Really.

---
 arch/arm64/kernel/bpi.S        |   20 ++++++++++++
 arch/arm64/kernel/cpu_errata.c |   68 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 87 insertions(+), 1 deletion(-)

@@ -17,6 +17,7 @@
  */
 
 #include <linux/linkage.h>
+#include <linux/arm-smccc.h>
 
 .macro ventry target
 	.rept 31

@@ -85,3 +86,22 @@ ENTRY(__qcom_hyp_sanitize_link_stack_sta
 	.endr
 	ldp	x29, x30, [sp], #16
 ENTRY(__qcom_hyp_sanitize_link_stack_end)
+
+.macro smccc_workaround_1 inst
+	sub	sp, sp, #(8 * 4)
+	stp	x2, x3, [sp, #(8 * 0)]
+	stp	x0, x1, [sp, #(8 * 2)]
+	mov	w0, #ARM_SMCCC_ARCH_WORKAROUND_1
+	\inst	#0
+	ldp	x2, x3, [sp, #(8 * 0)]
+	ldp	x0, x1, [sp, #(8 * 2)]
+	add	sp, sp, #(8 * 4)
+.endm
+
+ENTRY(__smccc_workaround_1_smc_start)
+	smccc_workaround_1	smc
+ENTRY(__smccc_workaround_1_smc_end)
+
+ENTRY(__smccc_workaround_1_hvc_start)
+	smccc_workaround_1	hvc
+ENTRY(__smccc_workaround_1_hvc_end)

Patches currently in stable-queue which might be from [email protected] 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