xref: /llvm-project/compiler-rt/lib/asan/asan_globals_win.cpp (revision 53a81d4d26f0409de8a0655d7af90f2bea222a12)
1 //===-- asan_globals_win.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 // Global registration code that is linked into every Windows DLL and EXE.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "asan_interface_internal.h"
14 #if SANITIZER_WINDOWS
15 
16 namespace __asan {
17 
18 #pragma section(".ASAN$GA", read, write)
19 #pragma section(".ASAN$GZ", read, write)
20 extern "C" alignas(sizeof(__asan_global))
21     __declspec(allocate(".ASAN$GA")) __asan_global __asan_globals_start = {};
22 extern "C" alignas(sizeof(__asan_global))
23     __declspec(allocate(".ASAN$GZ")) __asan_global __asan_globals_end = {};
24 #pragma comment(linker, "/merge:.ASAN=.data")
25 
26 static void call_on_globals(void (*hook)(__asan_global *, uptr)) {
27   __asan_global *start = &__asan_globals_start + 1;
28   __asan_global *end = &__asan_globals_end;
29   uptr bytediff = (uptr)end - (uptr)start;
30   if (bytediff % sizeof(__asan_global) != 0) {
31 #  if defined(SANITIZER_DLL_THUNK) ||             \
32       defined(SANITIZER_DYNAMIC_RUNTIME_THUNK) || \
33       defined(SANITIZER_STATIC_RUNTIME_THUNK)
34     __debugbreak();
35 #else
36     CHECK("corrupt asan global array");
37 #endif
38   }
39   // We know end >= start because the linker sorts the portion after the dollar
40   // sign alphabetically.
41   uptr n = end - start;
42   hook(start, n);
43 }
44 
45 static void register_dso_globals() {
46   call_on_globals(&__asan_register_globals);
47 }
48 
49 static void unregister_dso_globals() {
50   call_on_globals(&__asan_unregister_globals);
51 }
52 
53 // Register globals
54 #pragma section(".CRT$XCU", long, read)
55 #pragma section(".CRT$XTX", long, read)
56 extern "C" __declspec(allocate(".CRT$XCU"))
57 void (*const __asan_dso_reg_hook)() = &register_dso_globals;
58 extern "C" __declspec(allocate(".CRT$XTX"))
59 void (*const __asan_dso_unreg_hook)() = &unregister_dso_globals;
60 
61 } // namespace __asan
62 
63 #endif  // SANITIZER_WINDOWS
64