Improve the ScopedHandle verifier.

chrome/app/close_handle_hook_win.cc

Index: chrome/app/close_handle_hook_win.cc
diff --git a/chrome/app/close_handle_hook_win.cc b/chrome/app/close_handle_hook_win.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ca0b01e76c331c38192e97e3eba0e380147a2dfe
--- /dev/null
+++ b/chrome/app/close_handle_hook_win.cc
@@ -0,0 +1,118 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/app/close_handle_hook_win.h"
+
+#include <Windows.h>
+
+#include <vector>
+
+#include "base/files/file_path.h"
+#include "base/lazy_instance.h"
+#include "base/strings/string16.h"
+#include "base/win/iat_patch_function.h"
+#include "base/win/scoped_handle.h"
+#include "chrome/common/chrome_version_info.h"
+
+namespace {
+
+typedef BOOL (WINAPI* CloseHandleType) (HANDLE handle);
+CloseHandleType g_close_function = NULL;
+
+// The entry point for CloseHandle interception. This function notifies the
+// verifier about the handle that is being closed, and calls the original
+// function.
+BOOL WINAPI CloseHandleHook(HANDLE handle) {
+  base::win::OnHandleBeingClosed(handle);
+  return g_close_function(handle);
+}
+
+// Keeps track of all the hooks needed to intercept CloseHandle.
+class CloseHandleHooks {
+ public:
+  CloseHandleHooks() {}
+  ~CloseHandleHooks() {}
+
+  void AddIATPatch(const base::string16& module);
+  void Unpatch();
+
+ private:
+  std::vector<base::win::IATPatchFunction*> hooks_;
+  DISALLOW_COPY_AND_ASSIGN(CloseHandleHooks);
+};
+base::LazyInstance<CloseHandleHooks> g_hooks = LAZY_INSTANCE_INITIALIZER;
+
+void CloseHandleHooks::AddIATPatch(const base::string16& module) {
+  if (module.empty())
+    return;
+
+  base::win::IATPatchFunction* patch = new base::win::IATPatchFunction;
+  patch->Patch(module.c_str(), "kernel32.dll", "CloseHandle", CloseHandleHook);
+  hooks_.push_back(patch);
+  if (!g_close_function) {
+    // Things are probably messed up if each intercepted function points to
+    // a different place, but we need only one function to call.
+    g_close_function =
+      reinterpret_cast<CloseHandleType>(patch->original_function());
+  }
+}
+
+void CloseHandleHooks::Unpatch() {
+  for (std::vector<base::win::IATPatchFunction*>::iterator it = hooks_.begin();
+       it != hooks_.end(); ++it) {
+    (*it)->Unpatch();
+  }
+}
+
+bool UseHooks() {
+  chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
+  if (channel == chrome::VersionInfo::CHANNEL_CANARY ||
+      channel == chrome::VersionInfo::CHANNEL_DEV) {
+    return true;
+  }
+
+  return false;
+}
+
+base::string16 GetModuleName(HMODULE module) {
+  base::string16 name;
+  if (!module)
+    return name;
+  wchar_t buffer[MAX_PATH];
+  int rv = GetModuleFileName(module, buffer, MAX_PATH);
+  if (rv == MAX_PATH)
+    return name;
+
+  buffer[MAX_PATH - 1] = L'\0';
+  name.assign(buffer);
+  base::FilePath path(name);
+  return path.BaseName().AsUTF16Unsafe();
+}
+
+HMODULE GetChromeDLLModule() {
+  HMODULE module;
+  if (!GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
+                             GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+                         reinterpret_cast<wchar_t*>(&GetChromeDLLModule),
+                         &module)) {
+    return NULL;
+  }
+  return module;
+}
+
+}  // namespace
+
+void InstallCloseHandleHooks() {
+  if (!UseHooks())
+    return;
+
+  base::win::EnableHandleVerifier();
+  CloseHandleHooks* hooks = g_hooks.Pointer();
+  hooks->AddIATPatch(L"chrome.exe");
+  hooks->AddIATPatch(GetModuleName(GetChromeDLLModule()));

[cpu_(ooo_6.6-7.5), 2014/08/22 01:52:05]

can we just instead 
AddIATPatch(L"chrome.dll") and "chrome_child.dll" and have the AddPatch handle
failure?

[rvargas (doing something else), 2014/08/22 02:10:32]

Patch() does LoadLibrary so it will not fail. And we'll need GetModuleName()
anyway to patch all DLLs loaded on the process :)

[cpu_(ooo_6.6-7.5), 2014/08/22 22:10:20]

Acknowledged.

+}
+
+void RemoveCloseHandleHooks() {
+  g_hooks.Get().Unpatch();
+}