1  //===-- hwasan_mapping.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  /// \file
      10  /// This file is a part of HWAddressSanitizer and defines memory mapping.
      11  ///
      12  //===----------------------------------------------------------------------===//
      13  
      14  #ifndef HWASAN_MAPPING_H
      15  #define HWASAN_MAPPING_H
      16  
      17  #include "sanitizer_common/sanitizer_internal_defs.h"
      18  #include "hwasan_interface_internal.h"
      19  
      20  // Typical mapping on Linux/x86_64:
      21  // with dynamic shadow mapped at [0x770d59f40000, 0x7f0d59f40000]:
      22  // || [0x7f0d59f40000, 0x7fffffffffff] || HighMem    ||
      23  // || [0x7efe2f934000, 0x7f0d59f3ffff] || HighShadow ||
      24  // || [0x7e7e2f934000, 0x7efe2f933fff] || ShadowGap  ||
      25  // || [0x770d59f40000, 0x7e7e2f933fff] || LowShadow  ||
      26  // || [0x000000000000, 0x770d59f3ffff] || LowMem     ||
      27  
      28  // Typical mapping on Android/AArch64
      29  // with dynamic shadow mapped: [0x007477480000, 0x007c77480000]:
      30  // || [0x007c77480000, 0x007fffffffff] || HighMem    ||
      31  // || [0x007c3ebc8000, 0x007c7747ffff] || HighShadow ||
      32  // || [0x007bbebc8000, 0x007c3ebc7fff] || ShadowGap  ||
      33  // || [0x007477480000, 0x007bbebc7fff] || LowShadow  ||
      34  // || [0x000000000000, 0x00747747ffff] || LowMem     ||
      35  
      36  // Reasonable values are 4 (for 1/16th shadow) and 6 (for 1/64th).
      37  constexpr uptr kShadowScale = 4;
      38  constexpr uptr kShadowAlignment = 1ULL << kShadowScale;
      39  
      40  namespace __hwasan {
      41  
      42  extern uptr kLowMemStart;
      43  extern uptr kLowMemEnd;
      44  extern uptr kLowShadowEnd;
      45  extern uptr kLowShadowStart;
      46  extern uptr kHighShadowStart;
      47  extern uptr kHighShadowEnd;
      48  extern uptr kHighMemStart;
      49  extern uptr kHighMemEnd;
      50  
      51  inline uptr GetShadowOffset() {
      52    return SANITIZER_FUCHSIA ? 0 : __hwasan_shadow_memory_dynamic_address;
      53  }
      54  inline uptr MemToShadow(uptr untagged_addr) {
      55    return (untagged_addr >> kShadowScale) + GetShadowOffset();
      56  }
      57  inline uptr ShadowToMem(uptr shadow_addr) {
      58    return (shadow_addr - GetShadowOffset()) << kShadowScale;
      59  }
      60  inline uptr MemToShadowSize(uptr size) {
      61    return size >> kShadowScale;
      62  }
      63  
      64  bool MemIsApp(uptr p);
      65  
      66  inline bool MemIsShadow(uptr p) {
      67    return (kLowShadowStart <= p && p <= kLowShadowEnd) ||
      68           (kHighShadowStart <= p && p <= kHighShadowEnd);
      69  }
      70  
      71  uptr GetAliasRegionStart();
      72  
      73  }  // namespace __hwasan
      74  
      75  #endif  // HWASAN_MAPPING_H