1//===-- sanitizer_ptrauth.h -------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef SANITIZER_PTRAUTH_H
10#define SANITIZER_PTRAUTH_H
11
12#if __has_feature(ptrauth_intrinsics)
13# include <ptrauth.h>
14#elif defined(__ARM_FEATURE_PAC_DEFAULT) && !defined(__APPLE__)
15// On the stack the link register is protected with Pointer
16// Authentication Code when compiled with -mbranch-protection.
17// Let's stripping the PAC unconditionally because xpaclri is in
18// the NOP space so will do nothing when it is not enabled or not available.
19# define ptrauth_strip(__value, __key) \
20 ({ \
21 __typeof(__value) ret; \
22 asm volatile( \
23 "mov x30, %1\n\t" \
24 "hint #7\n\t" \
25 "mov %0, x30\n\t" \
26 "mov x30, xzr\n\t" \
27 : "=r"(ret) \
28 : "r"(__value) \
29 : "x30"); \
30 ret; \
31 })
32# define ptrauth_auth_data(__value, __old_key, __old_data) __value
33# define ptrauth_string_discriminator(__string) ((int)0)
34#else
35// Copied from <ptrauth.h>
36# define ptrauth_strip(__value, __key) __value
37# define ptrauth_auth_data(__value, __old_key, __old_data) __value
38# define ptrauth_string_discriminator(__string) ((int)0)
39#endif
40
41#define STRIP_PAC_PC(pc) ((uptr)ptrauth_strip(pc, 0))
42
43#endif // SANITIZER_PTRAUTH_H
44