LXR linux/include/linux/cfi.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Clang Control Flow Integrity (CFI) support.
   4 *
   5 * Copyright (C) 2021 Google LLC
   6 */
   7#ifndef _LINUX_CFI_H
   8#define _LINUX_CFI_H
   9
  10#ifdef CONFIG_CFI_CLANG
  11typedef void (*cfi_check_fn)(uint64_t id, void *ptr, void *diag);
  12
  13/* Compiler-generated function in each module, and the kernel */
  14extern void __cfi_check(uint64_t id, void *ptr, void *diag);
  15
  16/*
  17 * Force the compiler to generate a CFI jump table entry for a function
  18 * and store the jump table address to __cfi_jt_<function>.
  19 */
  20#define __CFI_ADDRESSABLE(fn, __attr) \
  21        const void *__cfi_jt_ ## fn __visible __attr = (void *)&fn
  22
  23#ifdef CONFIG_CFI_CLANG_SHADOW
  24
  25extern void cfi_module_add(struct module *mod, unsigned long base_addr);
  26extern void cfi_module_remove(struct module *mod, unsigned long base_addr);
  27
  28#else
  29
  30static inline void cfi_module_add(struct module *mod, unsigned long base_addr) {}
  31static inline void cfi_module_remove(struct module *mod, unsigned long base_addr) {}
  32
  33#endif /* CONFIG_CFI_CLANG_SHADOW */
  34
  35#else /* !CONFIG_CFI_CLANG */
  36
  37#define __CFI_ADDRESSABLE(fn, __attr)
  38
  39#endif /* CONFIG_CFI_CLANG */
  40
  41#endif /* _LINUX_CFI_H */
  42