1 //===-- asan_internal.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 // This file is a part of AddressSanitizer, an address sanity checker.
10 //
11 // ASan-private header which defines various general utilities.
12 //===----------------------------------------------------------------------===//
13 #ifndef ASAN_INTERNAL_H
14 #define ASAN_INTERNAL_H
15 
16 #include "asan_flags.h"
17 #include "asan_interface_internal.h"
18 #include "sanitizer_common/sanitizer_common.h"
19 #include "sanitizer_common/sanitizer_internal_defs.h"
20 #include "sanitizer_common/sanitizer_libc.h"
21 #include "sanitizer_common/sanitizer_stacktrace.h"
22 
23 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
24 #  error \
25       "The AddressSanitizer run-time should not be instrumented by AddressSanitizer"
26 #endif
27 
28 // Build-time configuration options.
29 
30 // If set, asan will intercept C++ exception api call(s).
31 #ifndef ASAN_HAS_EXCEPTIONS
32 #  define ASAN_HAS_EXCEPTIONS 1
33 #endif
34 
35 // If set, values like allocator chunk size, as well as defaults for some flags
36 // will be changed towards less memory overhead.
37 #ifndef ASAN_LOW_MEMORY
38 #  if SANITIZER_IOS || SANITIZER_ANDROID
39 #    define ASAN_LOW_MEMORY 1
40 #  else
41 #    define ASAN_LOW_MEMORY 0
42 #  endif
43 #endif
44 
45 #ifndef ASAN_DYNAMIC
46 #  ifdef PIC
47 #    define ASAN_DYNAMIC 1
48 #  else
49 #    define ASAN_DYNAMIC 0
50 #  endif
51 #endif
52 
53 // All internal functions in asan reside inside the __asan namespace
54 // to avoid namespace collisions with the user programs.
55 // Separate namespace also makes it simpler to distinguish the asan run-time
56 // functions from the instrumented user code in a profile.
57 namespace __asan {
58 
59 class AsanThread;
60 using __sanitizer::StackTrace;
61 
62 void AsanInitFromRtl();
63 bool TryAsanInitFromRtl();
64 
65 // asan_win.cpp
66 void InitializePlatformExceptionHandlers();
67 // Returns whether an address is a valid allocated system heap block.
68 // 'addr' must point to the beginning of the block.
69 bool IsSystemHeapAddress(uptr addr);
70 
71 // asan_rtl.cpp
72 void PrintAddressSpaceLayout();
73 void NORETURN ShowStatsAndAbort();
74 
75 // asan_shadow_setup.cpp
76 void InitializeShadowMemory();
77 
78 // asan_malloc_linux.cpp / asan_malloc_mac.cpp
79 void ReplaceSystemMalloc();
80 
81 // asan_linux.cpp / asan_mac.cpp / asan_win.cpp
82 uptr FindDynamicShadowStart();
83 void *AsanDoesNotSupportStaticLinkage();
84 void AsanCheckDynamicRTPrereqs();
85 void AsanCheckIncompatibleRT();
86 
87 // Unpoisons platform-specific stacks.
88 // Returns true if all stacks have been unpoisoned.
89 bool PlatformUnpoisonStacks();
90 
91 // asan_rtl.cpp
92 // Unpoison a region containing a stack.
93 // Performs a sanity check and warns if the bounds don't look right.
94 // The warning contains the type string to identify the stack type.
95 void UnpoisonStack(uptr bottom, uptr top, const char *type);
96 
97 // asan_thread.cpp
98 AsanThread *CreateMainThread();
99 
100 // Support function for __asan_(un)register_image_globals. Searches for the
101 // loaded image containing `needle' and then enumerates all global metadata
102 // structures declared in that image, applying `op' (e.g.,
103 // __asan_(un)register_globals) to them.
104 typedef void (*globals_op_fptr)(__asan_global *, uptr);
105 void AsanApplyToGlobals(globals_op_fptr op, const void *needle);
106 
107 void AsanOnDeadlySignal(int, void *siginfo, void *context);
108 
109 void SignContextStack(void *context);
110 void ReadContextStack(void *context, uptr *stack, uptr *ssize);
111 void StopInitOrderChecking();
112 
113 // Wrapper for TLS/TSD.
114 void AsanTSDInit(void (*destructor)(void *tsd));
115 void *AsanTSDGet();
116 void AsanTSDSet(void *tsd);
117 void PlatformTSDDtor(void *tsd);
118 
119 void AppendToErrorMessageBuffer(const char *buffer);
120 
121 void *AsanDlSymNext(const char *sym);
122 
123 // Returns `true` iff most of ASan init process should be skipped due to the
124 // ASan library being loaded via `dlopen()`. Platforms may perform any
125 // `dlopen()` specific initialization inside this function.
126 bool HandleDlopenInit();
127 
128 void InstallAtExitCheckLeaks();
129 void InstallAtForkHandler();
130 
131 #define ASAN_ON_ERROR() \
132   if (&__asan_on_error) \
133   __asan_on_error()
134 
135 bool AsanInited();
136 extern bool replace_intrin_cached;
137 extern void (*death_callback)(void);
138 // These magic values are written to shadow for better error
139 // reporting.
140 const int kAsanHeapLeftRedzoneMagic = 0xfa;
141 const int kAsanHeapFreeMagic = 0xfd;
142 const int kAsanStackLeftRedzoneMagic = 0xf1;
143 const int kAsanStackMidRedzoneMagic = 0xf2;
144 const int kAsanStackRightRedzoneMagic = 0xf3;
145 const int kAsanStackAfterReturnMagic = 0xf5;
146 const int kAsanInitializationOrderMagic = 0xf6;
147 const int kAsanUserPoisonedMemoryMagic = 0xf7;
148 const int kAsanContiguousContainerOOBMagic = 0xfc;
149 const int kAsanStackUseAfterScopeMagic = 0xf8;
150 const int kAsanGlobalRedzoneMagic = 0xf9;
151 const int kAsanInternalHeapMagic = 0xfe;
152 const int kAsanArrayCookieMagic = 0xac;
153 const int kAsanIntraObjectRedzone = 0xbb;
154 const int kAsanAllocaLeftMagic = 0xca;
155 const int kAsanAllocaRightMagic = 0xcb;
156 
157 static const uptr kCurrentStackFrameMagic = 0x41B58AB3;
158 static const uptr kRetiredStackFrameMagic = 0x45E0360E;
159 
160 }  // namespace __asan
161 
162 #endif  // ASAN_INTERNAL_H
163