1 files changed, 174 insertions, 0 deletions
diff --git a/toolkit/xre/dllservices/mozglue/ModuleLoadInfo.h b/toolkit/xre/dllservices/mozglue/ModuleLoadInfo.h
new file mode 100644
index 0000000000..807adaae0a
--- /dev/null
+++ b/toolkit/xre/dllservices/mozglue/ModuleLoadInfo.h
@@ -0,0 +1,174 @@
+/* -*- 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/. */
+
+#ifndef mozilla_ModuleLoadInfo_h
+#define mozilla_ModuleLoadInfo_h
+
+#include "mozilla/NativeNt.h"
+#include "mozilla/Vector.h"
+#include "mozilla/Unused.h"
+
+namespace mozilla {
+
+struct ModuleLoadInfo final {
+  enum class Status : uint32_t {
+    Loaded = 0,
+    Blocked,
+    Redirected,
+  };
+
+  // We do not provide these methods inside Gecko proper.
+#if !defined(MOZILLA_INTERNAL_API)
+
+  /**
+   * This constructor is for use by the LdrLoadDll hook.
+   */
+  explicit ModuleLoadInfo(PCUNICODE_STRING aRequestedDllName)
+      : mLoadTimeInfo(),
+        mThreadId(nt::RtlGetCurrentThreadId()),
+        mRequestedDllName(aRequestedDllName),
+        mBaseAddr(nullptr),
+        mStatus(Status::Loaded),
+        mIsDependent(false) {
+#  if defined(IMPL_MFBT)
+    ::QueryPerformanceCounter(&mBeginTimestamp);
+#  else
+    ::RtlQueryPerformanceCounter(&mBeginTimestamp);
+#  endif  // defined(IMPL_MFBT)
+  }
+
+  /**
+   * This constructor is used by the NtMapViewOfSection hook IF AND ONLY IF
+   * the LdrLoadDll hook did not already construct a ModuleLoadInfo for the
+   * current DLL load. This may occur while the loader is loading dependencies
+   * of another library.
+   */
+  ModuleLoadInfo(nt::AllocatedUnicodeString&& aSectionName,
+                 const void* aBaseAddr, Status aLoadStatus, bool aIsDependent)
+      : mLoadTimeInfo(),
+        mThreadId(nt::RtlGetCurrentThreadId()),
+        mSectionName(std::move(aSectionName)),
+        mBaseAddr(aBaseAddr),
+        mStatus(aLoadStatus),
+        mIsDependent(aIsDependent) {
+#  if defined(IMPL_MFBT)
+    ::QueryPerformanceCounter(&mBeginTimestamp);
+#  else
+    ::RtlQueryPerformanceCounter(&mBeginTimestamp);
+#  endif  // defined(IMPL_MFBT)
+  }
+
+  /**
+   * Marks the time that LdrLoadDll began loading this library.
+   */
+  void SetBeginLoadTimeStamp() {
+#  if defined(IMPL_MFBT)
+    ::QueryPerformanceCounter(&mLoadTimeInfo);
+#  else
+    ::RtlQueryPerformanceCounter(&mLoadTimeInfo);
+#  endif  // defined(IMPL_MFBT)
+  }
+
+  /**
+   * Marks the time that LdrLoadDll finished loading this library.
+   */
+  void SetEndLoadTimeStamp() {
+    LARGE_INTEGER endTimeStamp;
+#  if defined(IMPL_MFBT)
+    ::QueryPerformanceCounter(&endTimeStamp);
+#  else
+    ::RtlQueryPerformanceCounter(&endTimeStamp);
+#  endif  // defined(IMPL_MFBT)
+
+    LONGLONG& timeInfo = mLoadTimeInfo.QuadPart;
+    if (!timeInfo) {
+      return;
+    }
+
+    timeInfo = endTimeStamp.QuadPart - timeInfo;
+  }
+
+  /**
+   * Saves the current thread's call stack.
+   */
+  void CaptureBacktrace() {
+    const DWORD kMaxBacktraceSize = 512;
+
+    if (!mBacktrace.resize(kMaxBacktraceSize)) {
+      return;
+    }
+
+    // We don't use a Win32 variant here because Win32's CaptureStackBackTrace
+    // is just a macro that resolve to this function anyway.
+    WORD numCaptured = ::RtlCaptureStackBackTrace(2, kMaxBacktraceSize,
+                                                  mBacktrace.begin(), nullptr);
+    Unused << mBacktrace.resize(numCaptured);
+    // These backtraces might stick around for a while, so let's trim any
+    // excess memory.
+    mBacktrace.shrinkStorageToFit();
+  }
+
+#endif  // !defined(MOZILLA_INTERNAL_API)
+
+  ModuleLoadInfo(ModuleLoadInfo&&) = default;
+  ModuleLoadInfo& operator=(ModuleLoadInfo&&) = default;
+
+  ModuleLoadInfo() = delete;
+  ModuleLoadInfo(const ModuleLoadInfo&) = delete;
+  ModuleLoadInfo& operator=(const ModuleLoadInfo&) = delete;
+
+  /**
+   * A "bare" module load is one that was mapped without the code passing
+   * through a call to ntdll!LdrLoadDll.
+   */
+  bool IsBare() const {
+    // SetBeginLoadTimeStamp() and SetEndLoadTimeStamp() are only called by the
+    // LdrLoadDll hook, so when mLoadTimeInfo == 0, we know that we are bare.
+    return !mLoadTimeInfo.QuadPart;
+  }
+
+  /**
+   * Returns true for DLL loads where LdrLoadDll was called but
+   * NtMapViewOfSection was not. This will happen for DLL requests where the DLL
+   * was already mapped into memory by a previous request.
+   */
+  bool WasMapped() const { return !mSectionName.IsEmpty(); }
+
+  /**
+   * Returns true for DLL load which was denied by our blocklist.
+   */
+  bool WasDenied() const {
+    return mStatus == ModuleLoadInfo::Status::Blocked ||
+           mStatus == ModuleLoadInfo::Status::Redirected;
+  }
+
+  // Timestamp for the creation of this event
+  LARGE_INTEGER mBeginTimestamp;
+  // Duration of the LdrLoadDll call
+  LARGE_INTEGER mLoadTimeInfo;
+  // Thread ID of this DLL load
+  DWORD mThreadId;
+  // The name requested of LdrLoadDll by its caller
+  nt::AllocatedUnicodeString mRequestedDllName;
+  // The name of the DLL that backs section that was mapped by the loader. This
+  // string is the effective name of the DLL that was resolved by the loader's
+  // path search algorithm.
+  nt::AllocatedUnicodeString mSectionName;
+  // The base address of the module's mapped section
+  const void* mBaseAddr;
+  // If the module was successfully loaded, stack trace of the DLL load request
+  Vector<PVOID, 0, nt::RtlAllocPolicy> mBacktrace;
+  // The status of DLL load
+  Status mStatus;
+  // Whether the module is one of the executables's dependent modules or not
+  bool mIsDependent;
+};
+
+using ModuleLoadInfoVec = Vector<ModuleLoadInfo, 0, nt::RtlAllocPolicy>;
+
+}  // namespace mozilla
+
+#endif  // mozilla_ModuleLoadInfo_h