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