53b40e8d54
The use of ARMv8.3 pointer authentication (PAuth) is governed by fields in HCR_EL2, which trigger a 'trap to EL2' if not enabled. The reset value of these fields is 'architecturally unknown' so we must ensure that the fields are enabled (to disable the traps) if we are entering the kernel at EL1. The APK field disables PAuth instruction traps and the API field disables PAuth register traps Add code to disable the traps in armv8_switch_to_el1_m. Prior to doing so, it checks fields in the ID_AA64ISAR1_EL1 register to ensure pointer authentication is supported by the hardware. The runtime checks require a second temporary register, so add this to the EL1 transition macro signature and update 2 call sites. Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
52 lines
1.1 KiB
ArmAsm
52 lines
1.1 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* (C) Copyright 2013
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* David Feng <fenghua@phytium.com.cn>
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*/
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#include <asm-offsets.h>
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#include <config.h>
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#include <linux/linkage.h>
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#include <asm/macro.h>
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.pushsection .text.armv8_switch_to_el2, "ax"
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ENTRY(armv8_switch_to_el2)
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switch_el x6, 1f, 0f, 0f
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0:
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cmp x5, #ES_TO_AARCH64
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b.eq 2f
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/*
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* When loading 32-bit kernel, it will jump
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* to secure firmware again, and never return.
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*/
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bl armv8_el2_to_aarch32
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2:
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/*
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* x4 is kernel entry point or switch_to_el1
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* if CONFIG_ARMV8_SWITCH_TO_EL1 is defined.
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* When running in EL2 now, jump to the
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* address saved in x4.
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*/
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br x4
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1: armv8_switch_to_el2_m x4, x5, x6
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ENDPROC(armv8_switch_to_el2)
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.popsection
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.pushsection .text.armv8_switch_to_el1, "ax"
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ENTRY(armv8_switch_to_el1)
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switch_el x6, 0f, 1f, 0f
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0:
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/* x4 is kernel entry point. When running in EL1
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* now, jump to the address saved in x4.
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*/
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br x4
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1: armv8_switch_to_el1_m x4, x5, x6, x7
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ENDPROC(armv8_switch_to_el1)
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.popsection
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.pushsection .text.armv8_el2_to_aarch32, "ax"
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WEAK(armv8_el2_to_aarch32)
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ret
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ENDPROC(armv8_el2_to_aarch32)
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.popsection
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