1 files changed, 287 insertions, 0 deletions
diff --git a/browser/app/winlauncher/freestanding/LoaderPrivateAPI.cpp b/browser/app/winlauncher/freestanding/LoaderPrivateAPI.cpp
new file mode 100644
index 0000000000..527b6556a6
--- /dev/null
+++ b/browser/app/winlauncher/freestanding/LoaderPrivateAPI.cpp
@@ -0,0 +1,287 @@
+/* -*- 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 https://mozilla.org/MPL/2.0/. */
+
+#include "LoaderPrivateAPI.h"
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Types.h"
+#include "mozilla/Unused.h"
+#include "../DllBlocklistInit.h"
+#include "../ErrorHandler.h"
+
+using GlobalInitializerFn = void(__cdecl*)(void);
+
+// Allocation of static initialization section for the freestanding library
+#pragma section(".freestd$a", read)
+__declspec(allocate(".freestd$a")) static const GlobalInitializerFn
+    FreeStdStart = reinterpret_cast<GlobalInitializerFn>(0);
+
+#pragma section(".freestd$z", read)
+__declspec(allocate(".freestd$z")) static const GlobalInitializerFn FreeStdEnd =
+    reinterpret_cast<GlobalInitializerFn>(0);
+
+namespace mozilla {
+namespace freestanding {
+
+static RTL_RUN_ONCE gRunOnce = RTL_RUN_ONCE_INIT;
+
+// The contract for this callback is identical to the InitOnceCallback from
+// Win32 land; we're just using ntdll-layer types instead.
+static ULONG NTAPI DoOneTimeInit(PRTL_RUN_ONCE aRunOnce, PVOID aParameter,
+                                 PVOID* aContext) {
+  // Invoke every static initializer in the .freestd section
+  const GlobalInitializerFn* cur = &FreeStdStart + 1;
+  while (cur < &FreeStdEnd) {
+    if (*cur) {
+      (*cur)();
+    }
+
+    ++cur;
+  }
+
+  return TRUE;
+}
+
+/**
+ * This observer is only used until the mozglue observer connects itself.
+ * All we do here is accumulate the module loads into a vector.
+ * As soon as mozglue connects, we call |Forward| on mozglue's LoaderObserver
+ * to pass our vector on for further processing. This object then becomes
+ * defunct.
+ */
+class MOZ_ONLY_USED_TO_AVOID_STATIC_CONSTRUCTORS DefaultLoaderObserver final
+    : public nt::LoaderObserver {
+ public:
+  constexpr DefaultLoaderObserver() : mModuleLoads(nullptr) {}
+
+  void OnBeginDllLoad(void** aContext,
+                      PCUNICODE_STRING aRequestedDllName) final {}
+  bool SubstituteForLSP(PCUNICODE_STRING aLSPLeafName,
+                        PHANDLE aOutHandle) final {
+    return false;
+  }
+  void OnEndDllLoad(void* aContext, NTSTATUS aNtStatus,
+                    ModuleLoadInfo&& aModuleLoadInfo) final;
+  void Forward(nt::LoaderObserver* aNext) final;
+  void OnForward(ModuleLoadInfoVec&& aInfo) final {
+    MOZ_ASSERT_UNREACHABLE("Not valid in freestanding::DefaultLoaderObserver");
+  }
+
+ private:
+  mozilla::nt::SRWLock mLock;
+  ModuleLoadInfoVec* mModuleLoads;
+};
+
+class MOZ_ONLY_USED_TO_AVOID_STATIC_CONSTRUCTORS LoaderPrivateAPIImp final
+    : public LoaderPrivateAPI {
+ public:
+  // LoaderAPI
+  ModuleLoadInfo ConstructAndNotifyBeginDllLoad(
+      void** aContext, PCUNICODE_STRING aRequestedDllName) final;
+  bool SubstituteForLSP(PCUNICODE_STRING aLSPLeafName,
+                        PHANDLE aOutHandle) final;
+  void NotifyEndDllLoad(void* aContext, NTSTATUS aLoadNtStatus,
+                        ModuleLoadInfo&& aModuleLoadInfo) final;
+  nt::AllocatedUnicodeString GetSectionName(void* aSectionAddr) final;
+  nt::LoaderAPI::InitDllBlocklistOOPFnPtr GetDllBlocklistInitFn() final;
+  nt::LoaderAPI::HandleLauncherErrorFnPtr GetHandleLauncherErrorFn() final;
+
+  // LoaderPrivateAPI
+  void NotifyBeginDllLoad(void** aContext,
+                          PCUNICODE_STRING aRequestedDllName) final;
+  void NotifyBeginDllLoad(ModuleLoadInfo& aModuleLoadInfo, void** aContext,
+                          PCUNICODE_STRING aRequestedDllName) final;
+  void SetObserver(nt::LoaderObserver* aNewObserver) final;
+  bool IsDefaultObserver() const final;
+  nt::MemorySectionNameBuf GetSectionNameBuffer(void* aSectionAddr) final;
+};
+
+static void Init() {
+  DebugOnly<NTSTATUS> ntStatus =
+      ::RtlRunOnceExecuteOnce(&gRunOnce, &DoOneTimeInit, nullptr, nullptr);
+  MOZ_ASSERT(NT_SUCCESS(ntStatus));
+}
+
+}  // namespace freestanding
+}  // namespace mozilla
+
+static mozilla::freestanding::DefaultLoaderObserver gDefaultObserver;
+static mozilla::freestanding::LoaderPrivateAPIImp gPrivateAPI;
+
+static mozilla::nt::SRWLock gLoaderObserverLock;
+static mozilla::nt::LoaderObserver* gLoaderObserver = &gDefaultObserver;
+
+namespace mozilla {
+namespace freestanding {
+
+LoaderPrivateAPI& gLoaderPrivateAPI = gPrivateAPI;
+
+void DefaultLoaderObserver::OnEndDllLoad(void* aContext, NTSTATUS aNtStatus,
+                                         ModuleLoadInfo&& aModuleLoadInfo) {
+  // If the DLL load failed, or if the DLL was loaded by a previous request
+  // and thus was not mapped by this request, we do not save the ModuleLoadInfo.
+  if (!NT_SUCCESS(aNtStatus) || !aModuleLoadInfo.WasMapped()) {
+    return;
+  }
+
+  nt::AutoExclusiveLock lock(mLock);
+  if (!mModuleLoads) {
+    mModuleLoads = RtlNew<ModuleLoadInfoVec>();
+    if (!mModuleLoads) {
+      return;
+    }
+  }
+
+  Unused << mModuleLoads->emplaceBack(
+      std::forward<ModuleLoadInfo>(aModuleLoadInfo));
+}
+
+/**
+ * Pass mModuleLoads's data off to |aNext| for further processing.
+ */
+void DefaultLoaderObserver::Forward(nt::LoaderObserver* aNext) {
+  MOZ_ASSERT(aNext);
+  if (!aNext) {
+    return;
+  }
+
+  ModuleLoadInfoVec* moduleLoads = nullptr;
+
+  {  // Scope for lock
+    nt::AutoExclusiveLock lock(mLock);
+    moduleLoads = mModuleLoads;
+    mModuleLoads = nullptr;
+  }
+
+  if (!moduleLoads) {
+    return;
+  }
+
+  aNext->OnForward(std::move(*moduleLoads));
+  RtlDelete(moduleLoads);
+}
+
+ModuleLoadInfo LoaderPrivateAPIImp::ConstructAndNotifyBeginDllLoad(
+    void** aContext, PCUNICODE_STRING aRequestedDllName) {
+  ModuleLoadInfo loadInfo(aRequestedDllName);
+
+  NotifyBeginDllLoad(loadInfo, aContext, aRequestedDllName);
+
+  return loadInfo;
+}
+
+bool LoaderPrivateAPIImp::SubstituteForLSP(PCUNICODE_STRING aLSPLeafName,
+                                           PHANDLE aOutHandle) {
+  nt::AutoSharedLock lock(gLoaderObserverLock);
+  return gLoaderObserver->SubstituteForLSP(aLSPLeafName, aOutHandle);
+}
+
+void LoaderPrivateAPIImp::NotifyEndDllLoad(void* aContext,
+                                           NTSTATUS aLoadNtStatus,
+                                           ModuleLoadInfo&& aModuleLoadInfo) {
+  aModuleLoadInfo.SetEndLoadTimeStamp();
+
+  if (NT_SUCCESS(aLoadNtStatus)) {
+    aModuleLoadInfo.CaptureBacktrace();
+  }
+
+  nt::AutoSharedLock lock(gLoaderObserverLock);
+
+  // We need to notify the observer that the DLL load has ended even when
+  // |aLoadNtStatus| indicates a failure. This is to ensure that any resources
+  // acquired by the observer during OnBeginDllLoad are cleaned up.
+  gLoaderObserver->OnEndDllLoad(aContext, aLoadNtStatus,
+                                std::move(aModuleLoadInfo));
+}
+
+nt::AllocatedUnicodeString LoaderPrivateAPIImp::GetSectionName(
+    void* aSectionAddr) {
+  const HANDLE kCurrentProcess = reinterpret_cast<HANDLE>(-1);
+
+  nt::MemorySectionNameBuf buf;
+  NTSTATUS ntStatus =
+      ::NtQueryVirtualMemory(kCurrentProcess, aSectionAddr, MemorySectionName,
+                             &buf, sizeof(buf), nullptr);
+  if (!NT_SUCCESS(ntStatus)) {
+    return nt::AllocatedUnicodeString();
+  }
+
+  return nt::AllocatedUnicodeString(&buf.mSectionFileName);
+}
+
+nt::LoaderAPI::InitDllBlocklistOOPFnPtr
+LoaderPrivateAPIImp::GetDllBlocklistInitFn() {
+  return &InitializeDllBlocklistOOP;
+}
+
+nt::LoaderAPI::HandleLauncherErrorFnPtr
+LoaderPrivateAPIImp::GetHandleLauncherErrorFn() {
+  return &HandleLauncherError;
+}
+
+nt::MemorySectionNameBuf LoaderPrivateAPIImp::GetSectionNameBuffer(
+    void* aSectionAddr) {
+  const HANDLE kCurrentProcess = reinterpret_cast<HANDLE>(-1);
+
+  nt::MemorySectionNameBuf buf;
+  NTSTATUS ntStatus =
+      ::NtQueryVirtualMemory(kCurrentProcess, aSectionAddr, MemorySectionName,
+                             &buf, sizeof(buf), nullptr);
+  if (!NT_SUCCESS(ntStatus)) {
+    return nt::MemorySectionNameBuf();
+  }
+
+  return buf;
+}
+
+void LoaderPrivateAPIImp::NotifyBeginDllLoad(
+    void** aContext, PCUNICODE_STRING aRequestedDllName) {
+  nt::AutoSharedLock lock(gLoaderObserverLock);
+  gLoaderObserver->OnBeginDllLoad(aContext, aRequestedDllName);
+}
+
+void LoaderPrivateAPIImp::NotifyBeginDllLoad(
+    ModuleLoadInfo& aModuleLoadInfo, void** aContext,
+    PCUNICODE_STRING aRequestedDllName) {
+  NotifyBeginDllLoad(aContext, aRequestedDllName);
+  aModuleLoadInfo.SetBeginLoadTimeStamp();
+}
+
+void LoaderPrivateAPIImp::SetObserver(nt::LoaderObserver* aNewObserver) {
+  nt::LoaderObserver* prevLoaderObserver = nullptr;
+
+  nt::AutoExclusiveLock lock(gLoaderObserverLock);
+
+  MOZ_ASSERT(aNewObserver);
+  if (!aNewObserver) {
+    // This is unlikely, but we always want a valid observer, so use the
+    // gDefaultObserver if necessary.
+    gLoaderObserver = &gDefaultObserver;
+    return;
+  }
+
+  prevLoaderObserver = gLoaderObserver;
+  gLoaderObserver = aNewObserver;
+
+  MOZ_ASSERT(prevLoaderObserver);
+  if (!prevLoaderObserver) {
+    return;
+  }
+
+  // Now that we have a new observer, the previous observer must forward its
+  // data on to the new observer for processing.
+  prevLoaderObserver->Forward(aNewObserver);
+}
+
+bool LoaderPrivateAPIImp::IsDefaultObserver() const {
+  nt::AutoSharedLock lock(gLoaderObserverLock);
+  return gLoaderObserver == &gDefaultObserver;
+}
+
+void EnsureInitialized() { Init(); }
+
+}  // namespace freestanding
+}  // namespace mozilla