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

[Will Deacon]

commit 7b4a7b5e6fefd15f708f959dd43e188444e252ec upstream

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 and added linker script alias ]

Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Quentin Perret <qperret@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210319100146.1149909-3-qperret@xxxxxxxxxx
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
 arch/arm64/include/asm/hyp_image.h |  3 +++
 arch/arm64/kernel/image-vars.h     | 11 +++++++++++
 arch/arm64/kvm/hyp/nvhe/Makefile   |  4 ++++
 3 files changed, 18 insertions(+)

diff --git a/arch/arm64/include/asm/hyp_image.h b/arch/arm64/include/asm/hyp_image.h
index daa1a1da539e7..e068427560510 100644
--- a/arch/arm64/include/asm/hyp_image.h
+++ b/arch/arm64/include/asm/hyp_image.h
@@ -31,6 +31,9 @@
  */
 #define KVM_NVHE_ALIAS(sym)	kvm_nvhe_sym(sym) = sym;
 
+/* Defines a linker script alias for KVM nVHE hyp symbols */
+#define KVM_NVHE_ALIAS_HYP(first, sec)	kvm_nvhe_sym(first) = kvm_nvhe_sym(sec);
+
 #endif /* LINKER_SCRIPT */
 
 #endif /* __ARM64_HYP_IMAGE_H__ */
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index c615b285ff5b3..48e43b29a2d5f 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -103,6 +103,17 @@ KVM_NVHE_ALIAS(gic_nonsecure_priorities);
 KVM_NVHE_ALIAS(__start___kvm_ex_table);
 KVM_NVHE_ALIAS(__stop___kvm_ex_table);
 
+/* Position-independent library routines */
+KVM_NVHE_ALIAS_HYP(clear_page, __pi_clear_page);
+KVM_NVHE_ALIAS_HYP(copy_page, __pi_copy_page);
+KVM_NVHE_ALIAS_HYP(memcpy, __pi_memcpy);
+KVM_NVHE_ALIAS_HYP(memset, __pi_memset);
+
+#ifdef CONFIG_KASAN
+KVM_NVHE_ALIAS_HYP(__memcpy, __pi_memcpy);
+KVM_NVHE_ALIAS_HYP(__memset, __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 ddde15fe85f2f..230bba1a6716b 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -6,9 +6,13 @@
 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
 obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
 	 ../fpsimd.o ../hyp-entry.o
+obj-y += $(lib-objs)
 
 ##
 ## Build rules for compiling nVHE hyp code
-- 
2.30.2


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