1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Clang Control Flow Integrity (CFI) support.
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2019 Google LLC
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun #ifndef _LINUX_CFI_H
8*4882a593Smuzhiyun #define _LINUX_CFI_H
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #ifdef CONFIG_CFI_CLANG
11*4882a593Smuzhiyun typedef void (*cfi_check_fn)(uint64_t id, void *ptr, void *diag);
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun /* Compiler-generated function in each module, and the kernel */
14*4882a593Smuzhiyun extern void __cfi_check(uint64_t id, void *ptr, void *diag);
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun /*
17*4882a593Smuzhiyun * Force the compiler to generate a CFI jump table entry for a function
18*4882a593Smuzhiyun * and store the jump table address to __cfi_jt_<function>.
19*4882a593Smuzhiyun */
20*4882a593Smuzhiyun #define __CFI_ADDRESSABLE(fn) \
21*4882a593Smuzhiyun const void* __cfi_jt_ ## fn __visible = (void *)&fn;
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun #ifdef CONFIG_CFI_CLANG_SHADOW
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun extern void cfi_module_add(struct module *mod, unsigned long base_addr);
26*4882a593Smuzhiyun extern void cfi_module_remove(struct module *mod, unsigned long base_addr);
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun #else
29*4882a593Smuzhiyun
cfi_module_add(struct module * mod,unsigned long base_addr)30*4882a593Smuzhiyun static inline void cfi_module_add(struct module *mod, unsigned long base_addr) {}
cfi_module_remove(struct module * mod,unsigned long base_addr)31*4882a593Smuzhiyun static inline void cfi_module_remove(struct module *mod, unsigned long base_addr) {}
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun #endif /* CONFIG_CFI_CLANG_SHADOW */
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun #else /* !CONFIG_CFI_CLANG */
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun #define __CFI_ADDRESSABLE(fn)
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun #endif /* CONFIG_CFI_CLANG */
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun #endif /* _LINUX_CFI_H */
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