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Commit 36e5ae4d authored by Marc Zyngier's avatar Marc Zyngier Committed by Greg Kroah-Hartman
Browse files

arm64: Get rid of __smccc_workaround_1_hvc_* 



[ Upstream commit 22765f30 ]

The very existence of __smccc_workaround_1_hvc_* is a thinko, as
KVM will never use a HVC call to perform the branch prediction
invalidation. Even as a nested hypervisor, it would use an SMC
instruction.

Let's get rid of it.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 31ee977f

arch/arm64/kernel/bpi.S

+2 −10
Original line number Diff line number Diff line
@@ -56,21 +56,13 @@ ENTRY(__bp_harden_hyp_vecs_start) 
ENTRY(__bp_harden_hyp_vecs_end)





.macro smccc_workaround_1 inst

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

	\inst	#0

	smc	#0

	ldp	x2, x3, [sp, #(8 * 0)]

	ldp	x0, x1, [sp, #(8 * 2)]

	add	sp, sp, #(8 * 4)

.endm



ENTRY(__smccc_workaround_1_smc_start)

	smccc_workaround_1	smc

ENTRY(__smccc_workaround_1_smc_end)
 


ENTRY(__smccc_workaround_1_hvc_start)

	smccc_workaround_1	hvc

ENTRY(__smccc_workaround_1_hvc_end)

arch/arm64/kernel/cpu_errata.c

+3 −6
Original line number Diff line number Diff line
@@ -85,8 +85,6 @@ DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); 
#ifdef CONFIG_KVM

extern char __smccc_workaround_1_smc_start[];

extern char __smccc_workaround_1_smc_end[];

extern char __smccc_workaround_1_hvc_start[];

extern char __smccc_workaround_1_hvc_end[];



static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start,

				const char *hyp_vecs_end)
@@ -131,8 +129,6 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, 
#else

#define __smccc_workaround_1_smc_start		NULL

#define __smccc_workaround_1_smc_end		NULL

#define __smccc_workaround_1_hvc_start		NULL

#define __smccc_workaround_1_hvc_end		NULL



static void __install_bp_hardening_cb(bp_hardening_cb_t fn,

				      const char *hyp_vecs_start,
@@ -206,8 +202,9 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) 
		if ((int)res.a0 < 0)

			return;

		cb = call_hvc_arch_workaround_1;

		smccc_start = __smccc_workaround_1_hvc_start;

		smccc_end = __smccc_workaround_1_hvc_end;

		/* This is a guest, no need to patch KVM vectors */

		smccc_start = NULL;

		smccc_end = NULL;

		break;



	case PSCI_CONDUIT_SMC: