Commit e8b22d0f authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: Move the content of bpi.S to hyp-entry.S 



bpi.S was introduced as we were starting to build the Spectre v2
mitigation framework, and it was rather unclear that it would
become strictly KVM specific.

Now that the picture is a lot clearer, let's move the content
of that file to hyp-entry.S, where it actually belong.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 22765f30

arch/arm64/kernel/Makefile

+0 −2
Original line number Diff line number Diff line
@@ -55,8 +55,6 @@ arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o 
arm64-obj-$(CONFIG_CRASH_DUMP)		+= crash_dump.o

arm64-obj-$(CONFIG_ARM_SDE_INTERFACE)	+= sdei.o



arm64-obj-$(CONFIG_KVM_INDIRECT_VECTORS)+= bpi.o



obj-y					+= $(arm64-obj-y) vdso/ probes/

obj-m					+= $(arm64-obj-m)

head-y					:= head.o

arch/arm64/kernel/bpi.S

deleted100644 → 0
+0 −86
Original line number Diff line number Diff line 
/*

 * Contains CPU specific branch predictor invalidation sequences

 *

 * Copyright (C) 2018 ARM Ltd.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#include <linux/linkage.h>

#include <linux/arm-smccc.h>



#include <asm/alternative.h>

#include <asm/mmu.h>



.macro hyp_ventry

	.align 7

1:	.rept 27

	nop

	.endr

/*

 * The default sequence is to directly branch to the KVM vectors,

 * using the computed offset. This applies for VHE as well as

 * !ARM64_HARDEN_EL2_VECTORS.

 *

 * For ARM64_HARDEN_EL2_VECTORS configurations, this gets replaced

 * with:

 *

 * stp	x0, x1, [sp, #-16]!

 * movz	x0, #(addr & 0xffff)

 * movk	x0, #((addr >> 16) & 0xffff), lsl #16

 * movk	x0, #((addr >> 32) & 0xffff), lsl #32

 * br	x0

 *

 * Where addr = kern_hyp_va(__kvm_hyp_vector) + vector-offset + 4.

 * See kvm_patch_vector_branch for details.

 */

alternative_cb	kvm_patch_vector_branch

	b	__kvm_hyp_vector + (1b - 0b)

	nop

	nop

	nop

	nop

alternative_cb_end

.endm



.macro generate_vectors

0:

	.rept 16

	hyp_ventry

	.endr

	.org 0b + SZ_2K		// Safety measure

.endm





	.text

	.pushsection	.hyp.text, "ax"



	.align	11

ENTRY(__bp_harden_hyp_vecs_start)

	.rept BP_HARDEN_EL2_SLOTS

	generate_vectors

	.endr

ENTRY(__bp_harden_hyp_vecs_end)



	.popsection



ENTRY(__smccc_workaround_1_smc_start)

	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)

ENTRY(__smccc_workaround_1_smc_end)

arch/arm64/kernel/cpu_errata.c

+2 −2
Original line number Diff line number Diff line
@@ -86,7 +86,7 @@ atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); 


DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);



#ifdef CONFIG_KVM

#ifdef CONFIG_KVM_INDIRECT_VECTORS

extern char __smccc_workaround_1_smc_start[];

extern char __smccc_workaround_1_smc_end[];
@@ -137,7 +137,7 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, 
{

	__this_cpu_write(bp_hardening_data.fn, fn);

}

#endif	/* CONFIG_KVM */

#endif	/* CONFIG_KVM_INDIRECT_VECTORS */



static void  install_bp_hardening_cb(const struct arm64_cpu_capabilities *entry,

				     bp_hardening_cb_t fn,

arch/arm64/kvm/hyp/hyp-entry.S

+63 −1
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2015 - ARM Ltd

 * Copyright (C) 2015-2018 - ARM Ltd

 * Author: Marc Zyngier <marc.zyngier@arm.com>

 *

 * This program is free software; you can redistribute it and/or modify
@@ -24,6 +24,7 @@ 
#include <asm/kvm_arm.h>

#include <asm/kvm_asm.h>

#include <asm/kvm_mmu.h>

#include <asm/mmu.h>



	.text

	.pushsection	.hyp.text, "ax"
@@ -237,3 +238,64 @@ ENTRY(__kvm_hyp_vector) 
	invalid_vect	el1_fiq_invalid		// FIQ 32-bit EL1

	valid_vect	el1_error		// Error 32-bit EL1

ENDPROC(__kvm_hyp_vector)



#ifdef CONFIG_KVM_INDIRECT_VECTORS

.macro hyp_ventry

	.align 7

1:	.rept 27

	nop

	.endr

/*

 * The default sequence is to directly branch to the KVM vectors,

 * using the computed offset. This applies for VHE as well as

 * !ARM64_HARDEN_EL2_VECTORS.

 *

 * For ARM64_HARDEN_EL2_VECTORS configurations, this gets replaced

 * with:

 *

 * stp	x0, x1, [sp, #-16]!

 * movz	x0, #(addr & 0xffff)

 * movk	x0, #((addr >> 16) & 0xffff), lsl #16

 * movk	x0, #((addr >> 32) & 0xffff), lsl #32

 * br	x0

 *

 * Where addr = kern_hyp_va(__kvm_hyp_vector) + vector-offset + 4.

 * See kvm_patch_vector_branch for details.

 */

alternative_cb	kvm_patch_vector_branch

	b	__kvm_hyp_vector + (1b - 0b)

	nop

	nop

	nop

	nop

alternative_cb_end

.endm



.macro generate_vectors

0:

	.rept 16

	hyp_ventry

	.endr

	.org 0b + SZ_2K		// Safety measure

.endm



	.align	11

ENTRY(__bp_harden_hyp_vecs_start)

	.rept BP_HARDEN_EL2_SLOTS

	generate_vectors

	.endr

ENTRY(__bp_harden_hyp_vecs_end)



	.popsection



ENTRY(__smccc_workaround_1_smc_start)

	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)

ENTRY(__smccc_workaround_1_smc_end)

#endif

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