include/linux/cfi_types.h

   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 */