1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
//===-- asan_win_dynamic_runtime_thunk.cpp --------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of AddressSanitizer, an address sanity checker.
//
// This file defines things that need to be present in the application modules
// to interact with the ASan DLL runtime correctly and can't be implemented
// using the default "import library" generated when linking the DLL RTL.
//
// This includes:
// - creating weak aliases to default implementation imported from asan dll.
// - forwarding the detect_stack_use_after_return runtime option
// - working around deficiencies of the MD runtime
// - installing a custom SEH handler
//
//===----------------------------------------------------------------------===//
#ifdef SANITIZER_DYNAMIC_RUNTIME_THUNK
#define SANITIZER_IMPORT_INTERFACE 1
#include "sanitizer_common/sanitizer_win_defs.h"
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
// Define weak alias for all weak functions imported from asan dll.
#define INTERFACE_FUNCTION(Name)
#define INTERFACE_WEAK_FUNCTION(Name) WIN_WEAK_IMPORT_DEF(Name)
#include "asan_interface.inc"
// First, declare CRT sections we'll be using in this file
#pragma section(".CRT$XIB", long, read)
#pragma section(".CRT$XID", long, read)
#pragma section(".CRT$XCAB", long, read)
#pragma section(".CRT$XTW", long, read)
#pragma section(".CRT$XTY", long, read)
#pragma section(".CRT$XLAB", long, read)
////////////////////////////////////////////////////////////////////////////////
// Define a copy of __asan_option_detect_stack_use_after_return that should be
// used when linking an MD runtime with a set of object files on Windows.
//
// The ASan MD runtime dllexports '__asan_option_detect_stack_use_after_return',
// so normally we would just dllimport it. Unfortunately, the dllimport
// attribute adds __imp_ prefix to the symbol name of a variable.
// Since in general we don't know if a given TU is going to be used
// with a MT or MD runtime and we don't want to use ugly __imp_ names on Windows
// just to work around this issue, let's clone the variable that is constant
// after initialization anyways.
extern "C" {
__declspec(dllimport) int __asan_should_detect_stack_use_after_return();
int __asan_option_detect_stack_use_after_return;
__declspec(dllimport) void* __asan_get_shadow_memory_dynamic_address();
void* __asan_shadow_memory_dynamic_address;
}
static int InitializeClonedVariables() {
__asan_option_detect_stack_use_after_return =
__asan_should_detect_stack_use_after_return();
__asan_shadow_memory_dynamic_address =
__asan_get_shadow_memory_dynamic_address();
return 0;
}
static void NTAPI asan_thread_init(void *mod, unsigned long reason,
void *reserved) {
if (reason == DLL_PROCESS_ATTACH) InitializeClonedVariables();
}
// Our cloned variables must be initialized before C/C++ constructors. If TLS
// is used, our .CRT$XLAB initializer will run first. If not, our .CRT$XIB
// initializer is needed as a backup.
__declspec(allocate(".CRT$XIB")) int (*__asan_initialize_cloned_variables)() =
InitializeClonedVariables;
__declspec(allocate(".CRT$XLAB")) void (NTAPI *__asan_tls_init)(void *,
unsigned long, void *) = asan_thread_init;
////////////////////////////////////////////////////////////////////////////////
// For some reason, the MD CRT doesn't call the C/C++ terminators during on DLL
// unload or on exit. ASan relies on LLVM global_dtors to call
// __asan_unregister_globals on these events, which unfortunately doesn't work
// with the MD runtime, see PR22545 for the details.
// To work around this, for each DLL we schedule a call to UnregisterGlobals
// using atexit() that calls a small subset of C terminators
// where LLVM global_dtors is placed. Fingers crossed, no other C terminators
// are there.
extern "C" int __cdecl atexit(void (__cdecl *f)(void));
extern "C" void __cdecl _initterm(void *a, void *b);
namespace {
__declspec(allocate(".CRT$XTW")) void* before_global_dtors = 0;
__declspec(allocate(".CRT$XTY")) void* after_global_dtors = 0;
void UnregisterGlobals() {
_initterm(&before_global_dtors, &after_global_dtors);
}
int ScheduleUnregisterGlobals() {
return atexit(UnregisterGlobals);
}
} // namespace
// We need to call 'atexit(UnregisterGlobals);' as early as possible, but after
// atexit() is initialized (.CRT$XIC). As this is executed before C++
// initializers (think ctors for globals), UnregisterGlobals gets executed after
// dtors for C++ globals.
__declspec(allocate(".CRT$XID"))
int (*__asan_schedule_unregister_globals)() = ScheduleUnregisterGlobals;
////////////////////////////////////////////////////////////////////////////////
// ASan SEH handling.
// We need to set the ASan-specific SEH handler at the end of CRT initialization
// of each module (see also asan_win.cpp).
extern "C" {
__declspec(dllimport) int __asan_set_seh_filter();
static int SetSEHFilter() { return __asan_set_seh_filter(); }
// Unfortunately, putting a pointer to __asan_set_seh_filter into
// __asan_intercept_seh gets optimized out, so we have to use an extra function.
__declspec(allocate(".CRT$XCAB")) int (*__asan_seh_interceptor)() =
SetSEHFilter;
}
WIN_FORCE_LINK(__asan_dso_reg_hook)
#endif // SANITIZER_DYNAMIC_RUNTIME_THUNK
|
