| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
| 2 | /* |
| 3 | * Copyright (C) 2022 ARM Ltd. |
| 4 | */ |
| 5 | #ifndef __ASM_VECTORS_H |
| 6 | #define __ASM_VECTORS_H |
| 7 | |
| 8 | #include <linux/bug.h> |
| 9 | #include <linux/percpu.h> |
| 10 | |
| 11 | #include <asm/fixmap.h> |
| 12 | |
| 13 | extern char vectors[]; |
| 14 | extern char tramp_vectors[]; |
| 15 | extern char __bp_harden_el1_vectors[]; |
| 16 | |
| 17 | /* |
| 18 | * Note: the order of this enum corresponds to two arrays in entry.S: |
| 19 | * tramp_vecs and __bp_harden_el1_vectors. By default the canonical |
| 20 | * 'full fat' vectors are used directly. |
| 21 | */ |
| 22 | enum arm64_bp_harden_el1_vectors { |
| 23 | #ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY |
| 24 | /* |
| 25 | * Perform the BHB loop mitigation, before branching to the canonical |
| 26 | * vectors. |
| 27 | */ |
| 28 | EL1_VECTOR_BHB_LOOP, |
| 29 | |
| 30 | /* |
| 31 | * Make the SMC call for firmware mitigation, before branching to the |
| 32 | * canonical vectors. |
| 33 | */ |
| 34 | EL1_VECTOR_BHB_FW, |
| 35 | |
| 36 | /* |
| 37 | * Use the ClearBHB instruction, before branching to the canonical |
| 38 | * vectors. |
| 39 | */ |
| 40 | EL1_VECTOR_BHB_CLEAR_INSN, |
| 41 | #endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */ |
| 42 | |
| 43 | /* |
| 44 | * Remap the kernel before branching to the canonical vectors. |
| 45 | */ |
| 46 | EL1_VECTOR_KPTI, |
| 47 | }; |
| 48 | |
| 49 | #ifndef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY |
| 50 | #define EL1_VECTOR_BHB_LOOP -1 |
| 51 | #define EL1_VECTOR_BHB_FW -1 |
| 52 | #define EL1_VECTOR_BHB_CLEAR_INSN -1 |
| 53 | #endif /* !CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */ |
| 54 | |
| 55 | /* The vectors to use on return from EL0. e.g. to remap the kernel */ |
| 56 | DECLARE_PER_CPU_READ_MOSTLY(const char *, this_cpu_vector); |
| 57 | |
| 58 | #ifndef CONFIG_UNMAP_KERNEL_AT_EL0 |
| 59 | #define TRAMP_VALIAS 0ul |
| 60 | #endif |
| 61 | |
| 62 | static inline const char * |
| 63 | arm64_get_bp_hardening_vector(enum arm64_bp_harden_el1_vectors slot) |
| 64 | { |
| 65 | if (arm64_kernel_unmapped_at_el0()) |
| 66 | return (char *)(TRAMP_VALIAS + SZ_2K * slot); |
| 67 | |
| 68 | WARN_ON_ONCE(slot == EL1_VECTOR_KPTI); |
| 69 | |
| 70 | return __bp_harden_el1_vectors + SZ_2K * slot; |
| 71 | } |
| 72 | |
| 73 | #endif /* __ASM_VECTORS_H */ |