1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Clang Control Flow Integrity (CFI) type definitions.
4  */
5 #ifndef _LINUX_CFI_TYPES_H
6 #define _LINUX_CFI_TYPES_H
7 
8 #ifdef __ASSEMBLY__
9 #include <linux/linkage.h>
10 
11 #ifdef CONFIG_CFI_CLANG
12 /*
13  * Use the __kcfi_typeid_<function> type identifier symbol to
14  * annotate indirectly called assembly functions. The compiler emits
15  * these symbols for all address-taken function declarations in C
16  * code.
17  */
18 #ifndef __CFI_TYPE
19 #define __CFI_TYPE(name)				\
20 	.4byte __kcfi_typeid_##name
21 #endif
22 
23 #define SYM_TYPED_ENTRY(name, linkage, align...)	\
24 	linkage(name) ASM_NL				\
25 	align ASM_NL					\
26 	__CFI_TYPE(name) ASM_NL				\
27 	name:
28 
29 #define SYM_TYPED_START(name, linkage, align...)	\
30 	SYM_TYPED_ENTRY(name, linkage, align)
31 
32 #else /* CONFIG_CFI_CLANG */
33 
34 #define SYM_TYPED_START(name, linkage, align...)	\
35 	SYM_START(name, linkage, align)
36 
37 #endif /* CONFIG_CFI_CLANG */
38 
39 #ifndef SYM_TYPED_FUNC_START
40 #define SYM_TYPED_FUNC_START(name) 			\
41 	SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
42 #endif
43 
44 #endif /* __ASSEMBLY__ */
45 #endif /* _LINUX_CFI_TYPES_H */
46