libsanitizer/asan/asan_globals_win.cpp

   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" __declspec(allocate(".ASAN$GA"))
  21     ALIGNED(sizeof(__asan_global)) __asan_global __asan_globals_start = {};
  22 extern "C" __declspec(allocate(".ASAN$GZ"))
  23     ALIGNED(sizeof(__asan_global)) __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) || defined(SANITIZER_DYNAMIC_RUNTIME_THUNK)
  32     __debugbreak();
  33 #else
  34     CHECK("corrupt asan global array");
  35 #endif
  36   }
  37   // We know end >= start because the linker sorts the portion after the dollar
  38   // sign alphabetically.
  39   uptr n = end - start;
  40   hook(start, n);
  41 }
  42
  43 static void register_dso_globals() {
  44   call_on_globals(&__asan_register_globals);
  45 }
  46
  47 static void unregister_dso_globals() {
  48   call_on_globals(&__asan_unregister_globals);
  49 }
  50
  51 // Register globals
  52 #pragma section(".CRT$XCU", long, read)
  53 #pragma section(".CRT$XTX", long, read)
  54 extern "C" __declspec(allocate(".CRT$XCU"))
  55 void (*const __asan_dso_reg_hook)() = &register_dso_globals;
  56 extern "C" __declspec(allocate(".CRT$XTX"))
  57 void (*const __asan_dso_unreg_hook)() = &unregister_dso_globals;
  58
  59 } // namespace __asan
  60
  61 #endif  // SANITIZER_WINDOWS