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1 | //===-- sanitizer_win_dll_thunk.cpp ---------------------------------------===// | |
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 file defines a family of thunks that should be statically linked into | |
9 | // the DLLs that have instrumentation in order to delegate the calls to the | |
10 | // shared runtime that lives in the main binary. | |
11 | // See https://github.com/google/sanitizers/issues/209 for the details. | |
12 | //===----------------------------------------------------------------------===// | |
13 | ||
14 | #ifdef SANITIZER_DLL_THUNK | |
15 | #include "sanitizer_win_defs.h" | |
16 | #include "sanitizer_win_dll_thunk.h" | |
17 | #include "interception/interception.h" | |
18 | ||
19 | extern "C" { | |
20 | void *WINAPI GetModuleHandleA(const char *module_name); | |
21 | void abort(); | |
22 | } | |
23 | ||
24 | namespace __sanitizer { | |
25 | uptr dllThunkGetRealAddrOrDie(const char *name) { | |
26 | uptr ret = | |
27 | __interception::InternalGetProcAddress((void *)GetModuleHandleA(0), name); | |
28 | if (!ret) | |
29 | abort(); | |
30 | return ret; | |
31 | } | |
32 | ||
33 | int dllThunkIntercept(const char* main_function, uptr dll_function) { | |
34 | uptr wrapper = dllThunkGetRealAddrOrDie(main_function); | |
35 | if (!__interception::OverrideFunction(dll_function, wrapper, 0)) | |
36 | abort(); | |
37 | return 0; | |
38 | } | |
39 | ||
40 | int dllThunkInterceptWhenPossible(const char* main_function, | |
41 | const char* default_function, uptr dll_function) { | |
42 | uptr wrapper = __interception::InternalGetProcAddress( | |
43 | (void *)GetModuleHandleA(0), main_function); | |
44 | if (!wrapper) | |
45 | wrapper = dllThunkGetRealAddrOrDie(default_function); | |
46 | if (!__interception::OverrideFunction(dll_function, wrapper, 0)) | |
47 | abort(); | |
48 | return 0; | |
49 | } | |
50 | } // namespace __sanitizer | |
51 | ||
52 | // Include Sanitizer Common interface. | |
53 | #define INTERFACE_FUNCTION(Name) INTERCEPT_SANITIZER_FUNCTION(Name) | |
54 | #define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name) | |
55 | #include "sanitizer_common_interface.inc" | |
56 | ||
57 | #pragma section(".DLLTH$A", read) // NOLINT | |
58 | #pragma section(".DLLTH$Z", read) // NOLINT | |
59 | ||
60 | typedef void (*DllThunkCB)(); | |
61 | extern "C" { | |
62 | __declspec(allocate(".DLLTH$A")) DllThunkCB __start_dll_thunk; | |
63 | __declspec(allocate(".DLLTH$Z")) DllThunkCB __stop_dll_thunk; | |
64 | } | |
65 | ||
66 | // Disable compiler warnings that show up if we declare our own version | |
67 | // of a compiler intrinsic (e.g. strlen). | |
68 | #pragma warning(disable: 4391) | |
69 | #pragma warning(disable: 4392) | |
70 | ||
71 | extern "C" int __dll_thunk_init() { | |
72 | static bool flag = false; | |
73 | // __dll_thunk_init is expected to be called by only one thread. | |
74 | if (flag) return 0; | |
75 | flag = true; | |
76 | ||
77 | for (DllThunkCB *it = &__start_dll_thunk; it < &__stop_dll_thunk; ++it) | |
78 | if (*it) | |
79 | (*it)(); | |
80 | ||
81 | // In DLLs, the callbacks are expected to return 0, | |
82 | // otherwise CRT initialization fails. | |
83 | return 0; | |
84 | } | |
85 | ||
86 | // We want to call dll_thunk_init before C/C++ initializers / constructors are | |
87 | // executed, otherwise functions like memset might be invoked. | |
88 | #pragma section(".CRT$XIB", long, read) // NOLINT | |
89 | __declspec(allocate(".CRT$XIB")) int (*__dll_thunk_preinit)() = | |
90 | __dll_thunk_init; | |
91 | ||
92 | static void WINAPI dll_thunk_thread_init(void *mod, unsigned long reason, | |
93 | void *reserved) { | |
94 | if (reason == /*DLL_PROCESS_ATTACH=*/1) __dll_thunk_init(); | |
95 | } | |
96 | ||
97 | #pragma section(".CRT$XLAB", long, read) // NOLINT | |
98 | __declspec(allocate(".CRT$XLAB")) void (WINAPI *__dll_thunk_tls_init)(void *, | |
99 | unsigned long, void *) = dll_thunk_thread_init; | |
100 | ||
101 | #endif // SANITIZER_DLL_THUNK |