include/linux/cfi.h

   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 #ifndef cfi_get_offset
  15 static inline int cfi_get_offset(void)
  16 {
  17         return 0;
  18 }
  19 #endif
  20
  21 #ifdef CONFIG_CFI_CLANG
  22 enum bug_trap_type report_cfi_failure(struct pt_regs *regs, unsigned long addr,
  23                                       unsigned long *target, u32 type);
  24
  25 static inline enum bug_trap_type report_cfi_failure_noaddr(struct pt_regs *regs,
  26                                                            unsigned long addr)
  27 {
  28         return report_cfi_failure(regs, addr, NULL, 0);
  29 }
  30 #endif /* CONFIG_CFI_CLANG */
  31
  32 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
  33 bool is_cfi_trap(unsigned long addr);
  34 #else
  35 static inline bool is_cfi_trap(unsigned long addr) { return false; }
  36 #endif
  37
  38 #ifdef CONFIG_MODULES
  39 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
  40 void module_cfi_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
  41                          struct module *mod);
  42 #else
  43 static inline void module_cfi_finalize(const Elf_Ehdr *hdr,
  44                                        const Elf_Shdr *sechdrs,
  45                                        struct module *mod) {}
  46 #endif /* CONFIG_ARCH_USES_CFI_TRAPS */
  47 #endif /* CONFIG_MODULES */
  48
  49 #ifndef CFI_NOSEAL
  50 #define CFI_NOSEAL(x)
  51 #endif
  52
  53 #endif /* _LINUX_CFI_H */