[PATCH v3 02/15] arm64: kvm: Move __smccc_workaround_1_smc to .rodata

David Brazdil
2020-06-18T12:27:48Z

This snippet of assembly is used by cpu_errata.c to overwrite parts of KVM hyp
vector. Move it to its own source file and change its ELF section to .rodata.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
arch/arm64/kvm/hyp/Makefile | 1 +
arch/arm64/kvm/hyp/hyp-entry.S | 16 ----------------
arch/arm64/kvm/hyp/smccc_wa.S | 30 ++++++++++++++++++++++++++++++
3 files changed, 31 insertions(+), 16 deletions(-)
create mode 100644 arch/arm64/kvm/hyp/smccc_wa.S

diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index 8c9880783839..5d8357ddc234 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -7,6 +7,7 @@ ccflags-y += -fno-stack-protector -DDISABLE_BRANCH_PROFILING \
$(DISABLE_STACKLEAK_PLUGIN)

obj-$(CONFIG_KVM) += hyp.o
+obj-$(CONFIG_KVM_INDIRECT_VECTORS) += smccc_wa.o

hyp-y := vgic-v3-sr.o timer-sr.o aarch32.o vgic-v2-cpuif-proxy.o sysreg-sr.o \
debug-sr.o entry.o switch.o fpsimd.o tlb.o hyp-entry.o
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index 9c5cfb04170e..d362fad97cc8 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -318,20 +318,4 @@ SYM_CODE_START(__bp_harden_hyp_vecs)
1: .org __bp_harden_hyp_vecs + __BP_HARDEN_HYP_VECS_SZ
.org 1b
SYM_CODE_END(__bp_harden_hyp_vecs)
-
- .popsection
-
-SYM_CODE_START(__smccc_workaround_1_smc)
- esb
- sub sp, sp, #(8 * 4)
- stp x2, x3, [sp, #(8 * 0)]
- stp x0, x1, [sp, #(8 * 2)]
- mov w0, #ARM_SMCCC_ARCH_WORKAROUND_1
- smc #0
- ldp x2, x3, [sp, #(8 * 0)]
- ldp x0, x1, [sp, #(8 * 2)]
- add sp, sp, #(8 * 4)
-1: .org __smccc_workaround_1_smc + __SMCCC_WORKAROUND_1_SMC_SZ
- .org 1b
-SYM_CODE_END(__smccc_workaround_1_smc)
#endif
diff --git a/arch/arm64/kvm/hyp/smccc_wa.S b/arch/arm64/kvm/hyp/smccc_wa.S
new file mode 100644
index 000000000000..aa25b5428e77
--- /dev/null
+++ b/arch/arm64/kvm/hyp/smccc_wa.S
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2015-2018 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/arm-smccc.h>
+
+#include <asm/kvm_asm.h>
+#include <asm/kvm_mmu.h>
+
+ /*
+ * This is not executed directly and is instead copied into the vectors
+ * by install_bp_hardening_cb().
+ */
+ .data
+ .pushsection .rodata
+ .global __smccc_workaround_1_smc
+__smccc_workaround_1_smc:
+ esb
+ sub sp, sp, #(8 * 4)
+ stp x2, x3, [sp, #(8 * 0)]
+ stp x0, x1, [sp, #(8 * 2)]
+ mov w0, #ARM_SMCCC_ARCH_WORKAROUND_1
+ smc #0
+ ldp x2, x3, [sp, #(8 * 0)]
+ ldp x0, x1, [sp, #(8 * 2)]
+ add sp, sp, #(8 * 4)
+1: .org __smccc_workaround_1_smc + __SMCCC_WORKAROUND_1_SMC_SZ
+ .org 1b
--
2.27.0