1 //===-- sanitizer_win_dll_thunk.h -----------------------------------------===//
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 // This header provide helper macros to delegate calls to the shared runtime
9 // that lives in the main executable. It should be included to dll_thunks that
10 // will be linked to the dlls, when the sanitizer is a static library included
11 // in the main executable.
12 //===----------------------------------------------------------------------===//
13 #ifndef SANITIZER_WIN_DLL_THUNK_H
14 #define SANITIZER_WIN_DLL_THUNK_H
15 #include "sanitizer_internal_defs.h"
16
17 namespace __sanitizer {
18 uptr dllThunkGetRealAddrOrDie(const char *name);
19
20 int dllThunkIntercept(const char* main_function, uptr dll_function);
21
22 int dllThunkInterceptWhenPossible(const char* main_function,
23 const char* default_function, uptr dll_function);
24 }
25
26 extern "C" int __dll_thunk_init();
27
28 // ----------------- Function interception helper macros -------------------- //
29 // Override dll_function with main_function from main executable.
30 #define INTERCEPT_OR_DIE(main_function, dll_function) \
31 static int intercept_##dll_function() { \
32 return __sanitizer::dllThunkIntercept(main_function, (__sanitizer::uptr) \
33 dll_function); \
34 } \
35 __pragma(section(".DLLTH$M", long, read)) \
36 __declspec(allocate(".DLLTH$M")) int (*__dll_thunk_##dll_function)() = \
37 intercept_##dll_function;
38
39 // Try to override dll_function with main_function from main executable.
40 // If main_function is not present, override dll_function with default_function.
41 #define INTERCEPT_WHEN_POSSIBLE(main_function, default_function, dll_function) \
42 static int intercept_##dll_function() { \
43 return __sanitizer::dllThunkInterceptWhenPossible(main_function, \
44 default_function, (__sanitizer::uptr)dll_function); \
45 } \
46 __pragma(section(".DLLTH$M", long, read)) \
47 __declspec(allocate(".DLLTH$M")) int (*__dll_thunk_##dll_function)() = \
48 intercept_##dll_function;
49
50 // -------------------- Function interception macros ------------------------ //
51 // Special case of hooks -- ASan own interface functions. Those are only called
52 // after __asan_init, thus an empty implementation is sufficient.
53 #define INTERCEPT_SANITIZER_FUNCTION(name) \
54 extern "C" __declspec(noinline) void name() { \
55 volatile int prevent_icf = (__LINE__ << 8) ^ __COUNTER__; \
56 static const char function_name[] = #name; \
57 for (const char* ptr = &function_name[0]; *ptr; ++ptr) \
58 prevent_icf ^= *ptr; \
59 (void)prevent_icf; \
60 __debugbreak(); \
61 } \
62 INTERCEPT_OR_DIE(#name, name)
63
64 // Special case of hooks -- Weak functions, could be redefined in the main
65 // executable, but that is not necessary, so we shouldn't die if we can not find
66 // a reference. Instead, when the function is not present in the main executable
67 // we consider the default impl provided by asan library.
68 #define INTERCEPT_SANITIZER_WEAK_FUNCTION(name) \
69 extern "C" __declspec(noinline) void name() { \
70 volatile int prevent_icf = (__LINE__ << 8) ^ __COUNTER__; \
71 static const char function_name[] = #name; \
72 for (const char* ptr = &function_name[0]; *ptr; ++ptr) \
73 prevent_icf ^= *ptr; \
74 (void)prevent_icf; \
75 __debugbreak(); \
76 } \
77 INTERCEPT_WHEN_POSSIBLE(#name, STRINGIFY(WEAK_EXPORT_NAME(name)), name)
78
79 // We can't define our own version of strlen etc. because that would lead to
80 // link-time or even type mismatch errors. Instead, we can declare a function
81 // just to be able to get its address. Me may miss the first few calls to the
82 // functions since it can be called before __dll_thunk_init, but that would lead
83 // to false negatives in the startup code before user's global initializers,
84 // which isn't a big deal.
85 #define INTERCEPT_LIBRARY_FUNCTION(name) \
86 extern "C" void name(); \
87 INTERCEPT_OR_DIE(WRAPPER_NAME(name), name)
88
89 // Use these macros for functions that could be called before __dll_thunk_init()
90 // is executed and don't lead to errors if defined (free, malloc, etc).
91 #define INTERCEPT_WRAP_V_V(name) \
92 extern "C" void name() { \
93 typedef decltype(name) *fntype; \
94 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
95 fn(); \
96 } \
97 INTERCEPT_OR_DIE(#name, name);
98
99 #define INTERCEPT_WRAP_V_W(name) \
100 extern "C" void name(void *arg) { \
101 typedef decltype(name) *fntype; \
102 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
103 fn(arg); \
104 } \
105 INTERCEPT_OR_DIE(#name, name);
106
107 #define INTERCEPT_WRAP_V_WW(name) \
108 extern "C" void name(void *arg1, void *arg2) { \
109 typedef decltype(name) *fntype; \
110 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
111 fn(arg1, arg2); \
112 } \
113 INTERCEPT_OR_DIE(#name, name);
114
115 #define INTERCEPT_WRAP_V_WWW(name) \
116 extern "C" void name(void *arg1, void *arg2, void *arg3) { \
117 typedef decltype(name) *fntype; \
118 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
119 fn(arg1, arg2, arg3); \
120 } \
121 INTERCEPT_OR_DIE(#name, name);
122
123 #define INTERCEPT_WRAP_W_V(name) \
124 extern "C" void *name() { \
125 typedef decltype(name) *fntype; \
126 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
127 return fn(); \
128 } \
129 INTERCEPT_OR_DIE(#name, name);
130
131 #define INTERCEPT_WRAP_W_W(name) \
132 extern "C" void *name(void *arg) { \
133 typedef decltype(name) *fntype; \
134 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
135 return fn(arg); \
136 } \
137 INTERCEPT_OR_DIE(#name, name);
138
139 #define INTERCEPT_WRAP_W_WW(name) \
140 extern "C" void *name(void *arg1, void *arg2) { \
141 typedef decltype(name) *fntype; \
142 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
143 return fn(arg1, arg2); \
144 } \
145 INTERCEPT_OR_DIE(#name, name);
146
147 #define INTERCEPT_WRAP_W_WWW(name) \
148 extern "C" void *name(void *arg1, void *arg2, void *arg3) { \
149 typedef decltype(name) *fntype; \
150 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
151 return fn(arg1, arg2, arg3); \
152 } \
153 INTERCEPT_OR_DIE(#name, name);
154
155 #define INTERCEPT_WRAP_W_WWWW(name) \
156 extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4) { \
157 typedef decltype(name) *fntype; \
158 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
159 return fn(arg1, arg2, arg3, arg4); \
160 } \
161 INTERCEPT_OR_DIE(#name, name);
162
163 #define INTERCEPT_WRAP_W_WWWWW(name) \
164 extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4, \
165 void *arg5) { \
166 typedef decltype(name) *fntype; \
167 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
168 return fn(arg1, arg2, arg3, arg4, arg5); \
169 } \
170 INTERCEPT_OR_DIE(#name, name);
171
172 #define INTERCEPT_WRAP_W_WWWWWW(name) \
173 extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4, \
174 void *arg5, void *arg6) { \
175 typedef decltype(name) *fntype; \
176 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \
177 return fn(arg1, arg2, arg3, arg4, arg5, arg6); \
178 } \
179 INTERCEPT_OR_DIE(#name, name);
180
181 #endif // SANITIZER_WIN_DLL_THUNK_H