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 11 typedef void (*cfi_check_fn)(uint64_t id, void *ptr, void *diag); 12 13 /* Compiler-generated function in each module, and the kernel */ 14 extern 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 #else /* !CONFIG_CFI_CLANG */ 24 25 #ifdef CONFIG_X86_KERNEL_IBT 26 27 #define __CFI_ADDRESSABLE(fn, __attr) \ 28 const void *__cfi_jt_ ## fn __visible __attr = (void *)&fn 29 30 #endif /* CONFIG_X86_KERNEL_IBT */ 31 32 #endif /* CONFIG_CFI_CLANG */ 33 34 #ifndef __CFI_ADDRESSABLE 35 #define __CFI_ADDRESSABLE(fn, __attr) 36 #endif 37 38 #endif /* _LINUX_CFI_H */ 39