From: Marc Zyngier <marc.zyngier@arm.com>
Date: Wed, 14 Mar 2018 13:28:50 +0000 (+0000)
Subject: arm64: KVM: Move BP hardening vectors into .hyp.text section
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=4340ba80bd3a310d8eb9011df2e63c6371e28113;p=openwrt%2Fstaging%2Fblogic.git

arm64: KVM: Move BP hardening vectors into .hyp.text section

There is no reason why the BP hardening vectors shouldn't be part
of the HYP text at compile time, rather than being mapped at runtime.

Also introduce a new config symbol that controls the compilation
of bpi.S.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 8cd37eac6292..65dc225d019c 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -380,9 +380,7 @@ static inline void *kvm_get_hyp_vector(void)
 
 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);
+	return 0;
 }
 
 #else
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index b87541360f43..93bce17109a6 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -54,9 +54,7 @@ arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o
 arm64-obj-$(CONFIG_CRASH_DUMP)		+= crash_dump.o
 arm64-obj-$(CONFIG_ARM_SDE_INTERFACE)	+= sdei.o
 
-ifeq ($(CONFIG_KVM),y)
-arm64-obj-$(CONFIG_HARDEN_BRANCH_PREDICTOR)	+= bpi.o
-endif
+arm64-obj-$(CONFIG_KVM_INDIRECT_VECTORS)+= bpi.o
 
 obj-y					+= $(arm64-obj-y) vdso/ probes/
 obj-m					+= $(arm64-obj-m)
diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S
index e5de33513b5d..447188e2a664 100644
--- a/arch/arm64/kernel/bpi.S
+++ b/arch/arm64/kernel/bpi.S
@@ -48,6 +48,10 @@
 	ventry \target + 0x780
 .endm
 
+
+	.text
+	.pushsection	.hyp.text, "ax"
+
 	.align	11
 ENTRY(__bp_harden_hyp_vecs_start)
 	.rept 4
@@ -55,6 +59,8 @@ ENTRY(__bp_harden_hyp_vecs_start)
 	.endr
 ENTRY(__bp_harden_hyp_vecs_end)
 
+	.popsection
+
 ENTRY(__qcom_hyp_sanitize_link_stack_start)
 	stp     x29, x30, [sp, #-16]!
 	.rept	16
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 2257dfcc44cc..bd8cc03d7522 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -57,6 +57,9 @@ config KVM_ARM_PMU
 	  Adds support for a virtual Performance Monitoring Unit (PMU) in
 	  virtual machines.
 
+config KVM_INDIRECT_VECTORS
+       def_bool KVM && HARDEN_BRANCH_PREDICTOR
+
 source drivers/vhost/Kconfig
 
 endif # VIRTUALIZATION