[RFC PATCH 02/27] KVM: arm64: Link position-independent string routines into .hyp.text

From: Quentin Perret
Date: Tue Nov 17 2020 - 13:16:30 EST


From: Will Deacon <will@xxxxxxxxxx>

Pull clear_page(), copy_page(), memcpy() and memset() into the nVHE hyp
code and ensure that we always execute the '__pi_' entry point on the
offchance that it changes in future.

[ qperret: Commit title nits ]

Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Quentin Perret <qperret@xxxxxxxxxx>
---
arch/arm64/kernel/image-vars.h | 11 +++++++++++
arch/arm64/kvm/hyp/nvhe/Makefile | 4 ++++
2 files changed, 15 insertions(+)

diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 8539f34d7538..dd8ccc9efb6a 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -105,6 +105,17 @@ KVM_NVHE_ALIAS(__stop___kvm_ex_table);
/* Array containing bases of nVHE per-CPU memory regions. */
KVM_NVHE_ALIAS(kvm_arm_hyp_percpu_base);

+/* Position-independent library routines */
+__kvm_nvhe_clear_page = __kvm_nvhe___pi_clear_page;
+__kvm_nvhe_copy_page = __kvm_nvhe___pi_copy_page;
+__kvm_nvhe_memcpy = __kvm_nvhe___pi_memcpy;
+__kvm_nvhe_memset = __kvm_nvhe___pi_memset;
+
+#ifdef CONFIG_KASAN
+__kvm_nvhe___memcpy = __kvm_nvhe___pi_memcpy;
+__kvm_nvhe___memset = __kvm_nvhe___pi_memset;
+#endif
+
#endif /* CONFIG_KVM */

#endif /* __ARM64_KERNEL_IMAGE_VARS_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index 1f1e351c5fe2..590fdefb42dd 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -6,10 +6,14 @@
asflags-y := -D__KVM_NVHE_HYPERVISOR__
ccflags-y := -D__KVM_NVHE_HYPERVISOR__

+lib-objs := clear_page.o copy_page.o memcpy.o memset.o
+lib-objs := $(addprefix ../../../lib/, $(lib-objs))
+
obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \
hyp-main.o hyp-smp.o psci-relay.o
obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
../fpsimd.o ../hyp-entry.o ../exception.o
+obj-y += $(lib-objs)

##
## Build rules for compiling nVHE hyp code
--
2.29.2.299.gdc1121823c-goog