vectors.h
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2022 ARM Ltd.
*/
#ifndef __ASM_VECTORS_H
#define __ASM_VECTORS_H
#include <linux/bug.h>
#include <linux/percpu.h>
#include <asm/fixmap.h>
extern char vectors[];
extern char tramp_vectors[];
extern char __bp_harden_el1_vectors[];
/*
* Note: the order of this enum corresponds to two arrays in entry.S:
* tramp_vecs and __bp_harden_el1_vectors. By default the canonical
* 'full fat' vectors are used directly.
*/
enum arm64_bp_harden_el1_vectors {
#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
/*
* Perform the BHB loop mitigation, before branching to the canonical
* vectors.
*/
EL1_VECTOR_BHB_LOOP,
/*
* Make the SMC call for firmware mitigation, before branching to the
* canonical vectors.
*/
EL1_VECTOR_BHB_FW,
/*
* Use the ClearBHB instruction, before branching to the canonical
* vectors.
*/
EL1_VECTOR_BHB_CLEAR_INSN,
#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
/*
* Remap the kernel before branching to the canonical vectors.
*/
EL1_VECTOR_KPTI,
};
#ifndef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
#define EL1_VECTOR_BHB_LOOP -1
#define EL1_VECTOR_BHB_FW -1
#define EL1_VECTOR_BHB_CLEAR_INSN -1
#endif /* !CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
/* The vectors to use on return from EL0. e.g. to remap the kernel */
DECLARE_PER_CPU_READ_MOSTLY(const char *, this_cpu_vector);
#ifndef CONFIG_UNMAP_KERNEL_AT_EL0
#define TRAMP_VALIAS 0ul
#endif
static inline const char *
arm64_get_bp_hardening_vector(enum arm64_bp_harden_el1_vectors slot)
{
if (arm64_kernel_unmapped_at_el0())
return (char *)(TRAMP_VALIAS + SZ_2K * slot);
WARN_ON_ONCE(slot == EL1_VECTOR_KPTI);
return __bp_harden_el1_vectors + SZ_2K * slot;
}
#endif /* __ASM_VECTORS_H */