1 //===-- asan_win_common_runtime_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 //
9 // This file is a part of AddressSanitizer, an address sanity checker.
10 //
11 // This file defines things that need to be present in the application modules
12 // to interact with the ASan DLL runtime correctly and can't be implemented
13 // using the default "import library" generated when linking the DLL.
14 //
15 // This includes:
16 // - Cloning shadow memory dynamic address from ASAN DLL
17 // - Creating weak aliases to default implementation imported from asan dll
18 // - Forwarding the detect_stack_use_after_return runtime option
19 // - installing a custom SEH handler
20 //
21 //===----------------------------------------------------------------------===//
22
23 #if defined(SANITIZER_DYNAMIC_RUNTIME_THUNK) || \
24 defined(SANITIZER_STATIC_RUNTIME_THUNK)
25 # define SANITIZER_IMPORT_INTERFACE 1
26 # define WIN32_LEAN_AND_MEAN
27 # include "asan_win_common_runtime_thunk.h"
28
29 # include <windows.h>
30
31 # include "sanitizer_common/sanitizer_win_defs.h"
32 # include "sanitizer_common/sanitizer_win_thunk_interception.h"
33
34 // Define weak alias for all weak functions imported from asan dll.
35 # define INTERFACE_FUNCTION(Name)
36 # define INTERFACE_WEAK_FUNCTION(Name) REGISTER_WEAK_FUNCTION(Name)
37 # include "asan_interface.inc"
38
39 ////////////////////////////////////////////////////////////////////////////////
40 // Define a copy of __asan_option_detect_stack_use_after_return that should be
41 // used when linking an MD runtime with a set of object files on Windows.
42 //
43 // The ASan MD runtime dllexports '__asan_option_detect_stack_use_after_return',
44 // so normally we would just dllimport it. Unfortunately, the dllimport
45 // attribute adds __imp_ prefix to the symbol name of a variable.
46 // Since in general we don't know if a given TU is going to be used
47 // with a MT or MD runtime and we don't want to use ugly __imp_ names on Windows
48 // just to work around this issue, let's clone the variable that is constant
49 // after initialization anyways.
50
51 extern "C" {
52 __declspec(dllimport) int __asan_should_detect_stack_use_after_return();
53 int __asan_option_detect_stack_use_after_return;
54
55 __declspec(dllimport) void *__asan_get_shadow_memory_dynamic_address();
56 void *__asan_shadow_memory_dynamic_address;
57
__asan_initialize_cloned_variables()58 static void __asan_initialize_cloned_variables() {
59 __asan_option_detect_stack_use_after_return =
60 __asan_should_detect_stack_use_after_return();
61 __asan_shadow_memory_dynamic_address =
62 __asan_get_shadow_memory_dynamic_address();
63 }
64 }
65
asan_thunk_init()66 static int asan_thunk_init() {
67 __asan_initialize_cloned_variables();
68
69 # ifdef SANITIZER_STATIC_RUNTIME_THUNK
70 __asan_initialize_static_thunk();
71 # endif
72
73 return 0;
74 }
75
asan_thread_init(void * mod,unsigned long reason,void * reserved)76 static void WINAPI asan_thread_init(void *mod, unsigned long reason,
77 void *reserved) {
78 if (reason == DLL_PROCESS_ATTACH) {
79 asan_thunk_init();
80 }
81 }
82
83 // Our cloned variables must be initialized before C/C++ constructors. If TLS
84 // is used, our .CRT$XLAB initializer will run first. If not, our .CRT$XIB
85 // initializer is needed as a backup.
86 extern "C" __declspec(allocate(".CRT$XIB")) int (*__asan_thunk_init)() =
87 asan_thunk_init;
88 WIN_FORCE_LINK(__asan_thunk_init)
89
90 extern "C" __declspec(allocate(".CRT$XLAB")) void(WINAPI *__asan_tls_init)(
91 void *, unsigned long, void *) = asan_thread_init;
WIN_FORCE_LINK(__asan_tls_init)92 WIN_FORCE_LINK(__asan_tls_init)
93
94 ////////////////////////////////////////////////////////////////////////////////
95 // ASan SEH handling.
96 // We need to set the ASan-specific SEH handler at the end of CRT initialization
97 // of each module (see also asan_win.cpp).
98 extern "C" {
99 __declspec(dllimport) int __asan_set_seh_filter();
100 static int SetSEHFilter() { return __asan_set_seh_filter(); }
101
102 // Unfortunately, putting a pointer to __asan_set_seh_filter into
103 // __asan_intercept_seh gets optimized out, so we have to use an extra function.
104 extern "C" __declspec(allocate(".CRT$XCAB")) int (*__asan_seh_interceptor)() =
105 SetSEHFilter;
106 WIN_FORCE_LINK(__asan_seh_interceptor)
107 }
108
109 WIN_FORCE_LINK(__asan_dso_reg_hook)
110
111 #endif // defined(SANITIZER_DYNAMIC_RUNTIME_THUNK) ||
112 // defined(SANITIZER_STATIC_RUNTIME_THUNK)
113