Add HANDLE_FLAG_PROTECT_FROM_CLOSE flag to Tracked/ScopedHandle.

base/win/scoped_handle.cc

 // Copyright (c) 2012 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 "base/win/scoped_handle.h"
 
 #include <unordered_map>
 
 #include "base/debug/alias.h"
 #include "base/hash.h"
@@ skipping 134 matching lines @@
   closing_ = false;
 
   return true;
 }
 
 void ActiveVerifier::StartTracking(HANDLE handle, const void* owner,
                                    const void* pc1, const void* pc2) {
   if (!enabled_)
     return;
 
+  // Idea here is to make our handles non-closable until we close it ourselves.
+  if (!::SetHandleInformation(handle, HANDLE_FLAG_PROTECT_FROM_CLOSE,
+                              HANDLE_FLAG_PROTECT_FROM_CLOSE)) {
+    DWORD error = GetLastError();
+    // Even our unittests provide invalid/fabricated handles. Reducing scope
+    // of change to only deal with valid handles.
+    // TODO(shrikant): If this feature has to be permanent then decide right way
+    // for unit test ScopedProcessHandleInformation.
+    if (error != ERROR_INVALID_HANDLE) {

[cpu_(ooo_6.6-7.5), 2015/05/08 02:45:18]

what other error would SetHandleInformation could return?

it seems to me if we are ignoring the only probable error we might as well do
nothing

+      base::debug::Alias(&error);
+      CHECK(false);
+    }
+  }
+
   // Grab the thread id before the lock.
   DWORD thread_id = GetCurrentThreadId();
 
   AutoNativeLock lock(*lock_);
 
   Info handle_info = { owner, pc1, pc2, thread_id };
   std::pair<HANDLE, Info> item(handle, handle_info);
   std::pair<HandleMap::iterator, bool> result = map_.insert(item);
   if (!result.second) {
     Info other = result.first->second;
     base::debug::Alias(&other);
     CHECK(false);
   }
 }
 
 void ActiveVerifier::StopTracking(HANDLE handle, const void* owner,
                                   const void* pc1, const void* pc2) {
   if (!enabled_)
     return;
 
+  // We expect handle to be protected till this point.
+  DWORD flags = 0;
+  if (::GetHandleInformation(handle, &flags)) {
+    CHECK_NE(0U, (flags & HANDLE_FLAG_PROTECT_FROM_CLOSE));
+
+    // Unprotect handle so that it could be closed.
+    ::SetHandleInformation(handle, HANDLE_FLAG_PROTECT_FROM_CLOSE, 0);
+  }
+
   AutoNativeLock lock(*lock_);
   HandleMap::iterator i = map_.find(handle);
   if (i == map_.end())
     CHECK(false);
 
   Info other = i->second;
   if (other.owner != owner) {
     base::debug::Alias(&other);
     CHECK(false);
   }
@@ skipping 48 matching lines @@
 void DisableHandleVerifier() {
   return ActiveVerifier::Get()->Disable();
 }
 
 void OnHandleBeingClosed(HANDLE handle) {
   return ActiveVerifier::Get()->OnHandleBeingClosed(handle);
 }
 
 }  // namespace win
 }  // namespace base