linux-kernel - [PATCH 06/15] arm64: kvm: Move __smccc_workaround_1

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Message-Id: <20200430144831.59194-7-dbrazdil@google.com>
Date:   Thu, 30 Apr 2020 15:48:22 +0100
From:   David Brazdil <dbrazdil@...gle.com>
To:     Catalin Marinas <catalin.marinas@....com>,
        James Morse <james.morse@....com>,
        Julien Thierry <julien.thierry.kdev@...il.com>,
        Marc Zyngier <maz@...nel.org>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Will Deacon <will@...nel.org>
Cc:     kvmarm@...ts.cs.columbia.edu, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, David Brazdil <dbrazdil@...gle.com>
Subject: [PATCH 06/15] arm64: kvm: Move __smccc_workaround_1_smc to .rodata

This snippet of assembly is used by cpu_errata.c to overwrite parts of KVM hyp
vector. It is never directly executed, so move it from .text to .rodata.

Signed-off-by: David Brazdil <dbrazdil@...gle.com>
---
 arch/arm64/kvm/hyp/hyp-entry.S | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index 5986e1d78d3f..7e5f386c5c2d 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -364,6 +364,11 @@ SYM_CODE_END(__bp_harden_hyp_vecs)
 	.popsection
 
 #ifndef __HYPERVISOR__
+	/*
+	 * This is not executed directly and is instead copied into the vectors
+	 * by install_bp_hardening_cb().
+	 */
+	.pushsection	.rodata
 SYM_CODE_START(__smccc_workaround_1_smc)
 	esb
 	sub	sp, sp, #(8 * 4)
@@ -377,5 +382,6 @@ SYM_CODE_START(__smccc_workaround_1_smc)
 1:	.org __smccc_workaround_1_smc + __SMCCC_WORKAROUND_1_SMC_SZ
 	.org 1b
 SYM_CODE_END(__smccc_workaround_1_smc)
+	.popsection
 #endif /* __HYPERVISOR__ */
 #endif /* CONFIG_KVM_INDIRECT_VECTORS */
-- 
2.26.1