1 files changed, 102 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_win_dll_thunk.cc b/lib/sanitizer_common/sanitizer_win_dll_thunk.cc
new file mode 100644
index 000000000000..4fb4650be478
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_win_dll_thunk.cc
@@ -0,0 +1,102 @@
+//===-- sanitizer_win_dll_thunk.cc ----------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This file defines a family of thunks that should be statically linked into
+// the DLLs that have instrumentation in order to delegate the calls to the
+// shared runtime that lives in the main binary.
+// See https://github.com/google/sanitizers/issues/209 for the details.
+//===----------------------------------------------------------------------===//
+
+#ifdef SANITIZER_DLL_THUNK
+#include "sanitizer_win_defs.h"
+#include "sanitizer_win_dll_thunk.h"
+#include "interception/interception.h"
+
+extern "C" {
+void *WINAPI GetModuleHandleA(const char *module_name);
+void abort();
+}
+
+namespace __sanitizer {
+uptr dllThunkGetRealAddrOrDie(const char *name) {
+  uptr ret =
+      __interception::InternalGetProcAddress((void *)GetModuleHandleA(0), name);
+  if (!ret)
+    abort();
+  return ret;
+}
+
+int dllThunkIntercept(const char* main_function, uptr dll_function) {
+  uptr wrapper = dllThunkGetRealAddrOrDie(main_function);
+  if (!__interception::OverrideFunction(dll_function, wrapper, 0))
+    abort();
+  return 0;
+}
+
+int dllThunkInterceptWhenPossible(const char* main_function,
+    const char* default_function, uptr dll_function) {
+  uptr wrapper = __interception::InternalGetProcAddress(
+    (void *)GetModuleHandleA(0), main_function);
+  if (!wrapper)
+    wrapper = dllThunkGetRealAddrOrDie(default_function);
+  if (!__interception::OverrideFunction(dll_function, wrapper, 0))
+    abort();
+  return 0;
+}
+} // namespace __sanitizer
+
+// Include Sanitizer Common interface.
+#define INTERFACE_FUNCTION(Name) INTERCEPT_SANITIZER_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "sanitizer_common_interface.inc"
+
+#pragma section(".DLLTH$A", read)  // NOLINT
+#pragma section(".DLLTH$Z", read)  // NOLINT
+
+typedef void (*DllThunkCB)();
+extern "C" {
+__declspec(allocate(".DLLTH$A")) DllThunkCB __start_dll_thunk;
+__declspec(allocate(".DLLTH$Z")) DllThunkCB __stop_dll_thunk;
+}
+
+// Disable compiler warnings that show up if we declare our own version
+// of a compiler intrinsic (e.g. strlen).
+#pragma warning(disable: 4391)
+#pragma warning(disable: 4392)
+
+extern "C" int __dll_thunk_init() {
+  static bool flag = false;
+  // __dll_thunk_init is expected to be called by only one thread.
+  if (flag) return 0;
+  flag = true;
+
+  for (DllThunkCB *it = &__start_dll_thunk; it < &__stop_dll_thunk; ++it)
+    if (*it)
+      (*it)();
+
+  // In DLLs, the callbacks are expected to return 0,
+  // otherwise CRT initialization fails.
+  return 0;
+}
+
+// We want to call dll_thunk_init before C/C++ initializers / constructors are
+// executed, otherwise functions like memset might be invoked.
+#pragma section(".CRT$XIB", long, read)  // NOLINT
+__declspec(allocate(".CRT$XIB")) int (*__dll_thunk_preinit)() =
+    __dll_thunk_init;
+
+static void WINAPI dll_thunk_thread_init(void *mod, unsigned long reason,
+                                         void *reserved) {
+  if (reason == /*DLL_PROCESS_ATTACH=*/1) __dll_thunk_init();
+}
+
+#pragma section(".CRT$XLAB", long, read)  // NOLINT
+__declspec(allocate(".CRT$XLAB")) void (WINAPI *__dll_thunk_tls_init)(void *,
+    unsigned long, void *) = dll_thunk_thread_init;
+
+#endif // SANITIZER_DLL_THUNK