[RFC PATCH v2 02/26] KVM: arm64: Link position-independent string routines into .hyp.text

From: Quentin Perret <qperret@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Rob Herring <robh+dt@kernel.org>,
	Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org, android-kvm@google.com,
	linux-kernel@vger.kernel.org, kernel-team@android.com,
	kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org,
	Fuad Tabba <tabba@google.com>,
	Mark Rutland <mark.rutland@arm.com>,
	David Brazdil <dbrazdil@google.com>
Subject: [RFC PATCH v2 02/26] KVM: arm64: Link position-independent string routines into .hyp.text
Date: Fri,  8 Jan 2021 12:15:00 +0000	[thread overview]
Message-ID: <20210108121524.656872-3-qperret@google.com> (raw)
In-Reply-To: <20210108121524.656872-1-qperret@google.com>

From: Will Deacon <will@kernel.org>

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@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
---
 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 daa1a1da539e..e06842756051 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 39289d75118d..43f3a1d6e92d 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -102,6 +102,17 @@ 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_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 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
-- 
2.30.0.284.gd98b1dd5eaa7-goog

