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
51extern "C" {
52__declspec(dllimport) int __asan_should_detect_stack_use_after_return();
53int __asan_option_detect_stack_use_after_return;
54
55__declspec(dllimport) void *__asan_get_shadow_memory_dynamic_address();
56void *__asan_shadow_memory_dynamic_address;
57
58static 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
66static 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
76static 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.
86extern "C" __declspec(allocate(".CRT$XIB")) int (*__asan_thunk_init)() =
87 asan_thunk_init;
88WIN_FORCE_LINK(__asan_thunk_init)
89
90extern "C" __declspec(allocate(".CRT$XLAB")) void(WINAPI *__asan_tls_init)(
91 void *, unsigned long, void *) = asan_thread_init;
92WIN_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).
98extern "C" {
99__declspec(dllimport) int __asan_set_seh_filter();
100static 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.
104extern "C" __declspec(allocate(".CRT$XCAB")) int (*__asan_seh_interceptor)() =
105 SetSEHFilter;
106WIN_FORCE_LINK(__asan_seh_interceptor)
107}
108
109WIN_FORCE_LINK(__asan_dso_reg_hook)
110
111#endif // defined(SANITIZER_DYNAMIC_RUNTIME_THUNK) ||
112 // defined(SANITIZER_STATIC_RUNTIME_THUNK)
113

source code of compiler-rt/lib/asan/asan_win_common_runtime_thunk.cpp