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
cfi_get_offset(void)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
report_cfi_failure_noaddr(struct pt_regs * regs,unsigned long addr)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
is_cfi_trap(unsigned long addr)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
module_cfi_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * mod)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