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