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
76