| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | /* |
| 3 | * Clang Control Flow Integrity (CFI) support. |
| 4 | * |
| 5 | * Copyright (C) 2022 Google LLC |
| 6 | */ |
| 7 | #ifndef _LINUX_CFI_H |
| 8 | #define _LINUX_CFI_H |
| 9 | |
| 10 | #include <linux/bug.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <asm/cfi.h> |
| 13 | |
| 14 | extern bool cfi_warn; |
| 15 | |
| 16 | #ifndef cfi_get_offset |
| 17 | static inline int cfi_get_offset(void) |
| 18 | { |
| 19 | return 0; |
| 20 | } |
| 21 | #endif |
| 22 | |
| 23 | #ifdef CONFIG_CFI_CLANG |
| 24 | enum bug_trap_type report_cfi_failure(struct pt_regs *regs, unsigned long addr, |
| 25 | unsigned long *target, u32 type); |
| 26 | |
| 27 | static inline enum bug_trap_type report_cfi_failure_noaddr(struct pt_regs *regs, |
| 28 | unsigned long addr) |
| 29 | { |
| 30 | return report_cfi_failure(regs, addr, NULL, 0); |
| 31 | } |
| 32 | #endif /* CONFIG_CFI_CLANG */ |
| 33 | |
| 34 | #ifdef CONFIG_ARCH_USES_CFI_TRAPS |
| 35 | bool is_cfi_trap(unsigned long addr); |
| 36 | #else |
| 37 | static inline bool is_cfi_trap(unsigned long addr) { return false; } |
| 38 | #endif |
| 39 | |
| 40 | #ifdef CONFIG_MODULES |
| 41 | #ifdef CONFIG_ARCH_USES_CFI_TRAPS |
| 42 | void module_cfi_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, |
| 43 | struct module *mod); |
| 44 | #else |
| 45 | static inline void module_cfi_finalize(const Elf_Ehdr *hdr, |
| 46 | const Elf_Shdr *sechdrs, |
| 47 | struct module *mod) {} |
| 48 | #endif /* CONFIG_ARCH_USES_CFI_TRAPS */ |
| 49 | #endif /* CONFIG_MODULES */ |
| 50 | |
| 51 | #ifndef CFI_NOSEAL |
| 52 | #define CFI_NOSEAL(x) |
| 53 | #endif |
| 54 | |
| 55 | #endif /* _LINUX_CFI_H */ |
| 56 | |