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#ifndef cfi_get_offset
15static inline int cfi_get_offset(void)
16{
17	return 0;
18}
19#endif
20
21#ifdef CONFIG_CFI_CLANG
22enum bug_trap_type report_cfi_failure(struct pt_regs *regs, unsigned long addr,
23				      unsigned long *target, u32 type);
24
25static inline enum bug_trap_type report_cfi_failure_noaddr(struct pt_regs *regs,
26							   unsigned long addr)
27{
28	return report_cfi_failure(regs, addr, NULL, 0);
29}
30#endif /* CONFIG_CFI_CLANG */
31
32#ifdef CONFIG_ARCH_USES_CFI_TRAPS
33bool is_cfi_trap(unsigned long addr);
34#else
35static inline bool is_cfi_trap(unsigned long addr) { return false; }
36#endif
37
38#ifdef CONFIG_MODULES
39#ifdef CONFIG_ARCH_USES_CFI_TRAPS
40void module_cfi_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
41			 struct module *mod);
42#else
43static inline void module_cfi_finalize(const Elf_Ehdr *hdr,
44				       const Elf_Shdr *sechdrs,
45				       struct module *mod) {}
46#endif /* CONFIG_ARCH_USES_CFI_TRAPS */
47#endif /* CONFIG_MODULES */
48
49#ifndef CFI_NOSEAL
50#define CFI_NOSEAL(x)
51#endif
52
53#endif /* _LINUX_CFI_H */
54