llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h

42 lines
1.5 KiB
C++

//===-- sanitizer_ptrauth.h -------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef SANITIZER_PTRAUTH_H
#define SANITIZER_PTRAUTH_H
#if __has_feature(ptrauth_calls)
#include <ptrauth.h>
#elif defined(__ARM_FEATURE_PAC_DEFAULT) && !defined(__APPLE__)
inline unsigned long ptrauth_strip(void* __value, unsigned int __key) {
// On the stack the link register is protected with Pointer
// Authentication Code when compiled with -mbranch-protection.
// Let's stripping the PAC unconditionally because xpaclri is in
// the NOP space so will do nothing when it is not enabled or not available.
unsigned long ret;
asm volatile(
"mov x30, %1\n\t"
"hint #7\n\t" // xpaclri
"mov %0, x30\n\t"
: "=r"(ret)
: "r"(__value)
: "x30");
return ret;
}
#define ptrauth_auth_data(__value, __old_key, __old_data) __value
#define ptrauth_string_discriminator(__string) ((int)0)
#else
// Copied from <ptrauth.h>
#define ptrauth_strip(__value, __key) __value
#define ptrauth_auth_data(__value, __old_key, __old_data) __value
#define ptrauth_string_discriminator(__string) ((int)0)
#endif
#define STRIP_PAC_PC(pc) ((uptr)ptrauth_strip(pc, 0))
#endif // SANITIZER_PTRAUTH_H