1 files changed, 149 insertions, 0 deletions
diff --git a/toolkit/xre/dllservices/mozglue/LoaderObserver.cpp b/toolkit/xre/dllservices/mozglue/LoaderObserver.cpp
new file mode 100644
index 0000000000..d2014365c4
--- /dev/null
+++ b/toolkit/xre/dllservices/mozglue/LoaderObserver.cpp
@@ -0,0 +1,149 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "LoaderObserver.h"
+
+#include "mozilla/AutoProfilerLabel.h"
+#include "mozilla/BaseProfilerMarkers.h"
+#include "mozilla/glue/WindowsUnicode.h"
+#include "mozilla/StackWalk_windows.h"
+#include "mozilla/TimeStamp.h"
+
+namespace mozilla {
+
+extern glue::Win32SRWLock gDllServicesLock;
+extern glue::detail::DllServicesBase* gDllServices;
+
+namespace glue {
+
+void LoaderObserver::OnBeginDllLoad(void** aContext,
+                                    PCUNICODE_STRING aRequestedDllName) {
+  MOZ_ASSERT(aContext);
+  if (IsProfilerPresent()) {
+    UniquePtr<char[]> utf8RequestedDllName(WideToUTF8(aRequestedDllName));
+    BASE_PROFILER_MARKER_TEXT(
+        "DllLoad", OTHER, MarkerTiming::IntervalStart(),
+        mozilla::ProfilerString8View::WrapNullTerminatedString(
+            utf8RequestedDllName.get()));
+    *aContext = utf8RequestedDllName.release();
+  }
+
+#ifdef _M_AMD64
+  // Prevent the stack walker from suspending this thread when LdrLoadDll
+  // holds the RtlLookupFunctionEntry lock.
+  SuppressStackWalking();
+#endif
+}
+
+bool LoaderObserver::SubstituteForLSP(PCUNICODE_STRING aLSPLeafName,
+                                      PHANDLE aOutHandle) {
+  // Currently unsupported
+  return false;
+}
+
+void LoaderObserver::OnEndDllLoad(void* aContext, NTSTATUS aNtStatus,
+                                  ModuleLoadInfo&& aModuleLoadInfo) {
+#ifdef _M_AMD64
+  DesuppressStackWalking();
+#endif
+
+  if (aContext) {
+    UniquePtr<char[]> utf8RequestedDllName{static_cast<char*>(aContext)};
+    BASE_PROFILER_MARKER_TEXT(
+        "DllLoad", OTHER, MarkerTiming::IntervalEnd(),
+        mozilla::ProfilerString8View::WrapNullTerminatedString(
+            utf8RequestedDllName.get()));
+  }
+
+  // We want to record a denied DLL load regardless of |aNtStatus| because
+  // |aNtStatus| is set to access-denied when DLL load was blocked.
+  if ((!NT_SUCCESS(aNtStatus) && !aModuleLoadInfo.WasDenied()) ||
+      !aModuleLoadInfo.WasMapped()) {
+    return;
+  }
+
+  {  // Scope for lock
+    AutoSharedLock lock(gDllServicesLock);
+    if (gDllServices) {
+      gDllServices->DispatchDllLoadNotification(std::move(aModuleLoadInfo));
+      return;
+    }
+  }
+
+  // No dll services, save for later
+  AutoExclusiveLock lock(mLock);
+  if (!mEnabled) {
+    return;
+  }
+
+  if (!mModuleLoads) {
+    mModuleLoads = new ModuleLoadInfoVec();
+  }
+
+  Unused << mModuleLoads->emplaceBack(
+      std::forward<ModuleLoadInfo>(aModuleLoadInfo));
+}
+
+void LoaderObserver::Forward(nt::LoaderObserver* aNext) {
+  MOZ_ASSERT_UNREACHABLE(
+      "This implementation does not forward to any more "
+      "nt::LoaderObserver objects");
+}
+
+void LoaderObserver::Forward(detail::DllServicesBase* aNext) {
+  MOZ_ASSERT(aNext);
+  if (!aNext) {
+    return;
+  }
+
+  ModuleLoadInfoVec* moduleLoads = nullptr;
+
+  {  // Scope for lock
+    AutoExclusiveLock lock(mLock);
+    moduleLoads = mModuleLoads;
+    mModuleLoads = nullptr;
+  }
+
+  if (!moduleLoads) {
+    return;
+  }
+
+  aNext->DispatchModuleLoadBacklogNotification(std::move(*moduleLoads));
+  delete moduleLoads;
+}
+
+void LoaderObserver::Disable() {
+  ModuleLoadInfoVec* moduleLoads = nullptr;
+
+  {  // Scope for lock
+    AutoExclusiveLock lock(mLock);
+    moduleLoads = mModuleLoads;
+    mModuleLoads = nullptr;
+    mEnabled = false;
+  }
+
+  delete moduleLoads;
+}
+
+void LoaderObserver::OnForward(ModuleLoadInfoVec&& aInfo) {
+  AutoExclusiveLock lock(mLock);
+  if (!mModuleLoads) {
+    mModuleLoads = new ModuleLoadInfoVec();
+  }
+
+  MOZ_ASSERT(mModuleLoads->empty());
+  if (mModuleLoads->empty()) {
+    *mModuleLoads = std::move(aInfo);
+  } else {
+    // This should not happen, but we can handle it
+    for (auto&& item : aInfo) {
+      Unused << mModuleLoads->append(std::move(item));
+    }
+  }
+}
+
+}  // namespace glue
+}  // namespace mozilla