1 files changed, 124 insertions, 0 deletions
diff --git a/mozglue/misc/WindowsMapRemoteView.cpp b/mozglue/misc/WindowsMapRemoteView.cpp
new file mode 100644
index 0000000000..aca9979ab6
--- /dev/null
+++ b/mozglue/misc/WindowsMapRemoteView.cpp
@@ -0,0 +1,124 @@
+/* -*- 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 "mozilla/WindowsMapRemoteView.h"
+
+#include "mozilla/Assertions.h"
+#include "mozilla/DynamicallyLinkedFunctionPtr.h"
+
+#include <winternl.h>
+
+#if (NTDDI_VERSION < NTDDI_WIN10_RS2)
+
+// MapViewOfFile2 is just an inline function that calls MapViewOfFileNuma2 with
+// its preferred node set to NUMA_NO_PREFERRED_NODE
+WINBASEAPI PVOID WINAPI MapViewOfFileNuma2(HANDLE aFileMapping, HANDLE aProcess,
+                                           ULONG64 aOffset, PVOID aBaseAddress,
+                                           SIZE_T aViewSize,
+                                           ULONG aAllocationType,
+                                           ULONG aPageProtection,
+                                           ULONG aPreferredNode);
+
+WINBASEAPI BOOL WINAPI UnmapViewOfFile2(HANDLE aProcess, PVOID aBaseAddress,
+                                        ULONG aUnmapFlags);
+
+#endif  // (NTDDI_VERSION < NTDDI_WIN10_RS2)
+
+enum SECTION_INHERIT { ViewShare = 1, ViewUnmap = 2 };
+
+NTSTATUS NTAPI NtMapViewOfSection(
+    HANDLE aSection, HANDLE aProcess, PVOID* aBaseAddress, ULONG_PTR aZeroBits,
+    SIZE_T aCommitSize, PLARGE_INTEGER aSectionOffset, PSIZE_T aViewSize,
+    SECTION_INHERIT aInheritDisposition, ULONG aAllocationType,
+    ULONG aProtectionFlags);
+
+NTSTATUS NTAPI NtUnmapViewOfSection(HANDLE aProcess, PVOID aBaseAddress);
+
+static DWORD GetWin32ErrorCode(NTSTATUS aNtStatus) {
+  static const mozilla::StaticDynamicallyLinkedFunctionPtr<
+      decltype(&RtlNtStatusToDosError)>
+      pRtlNtStatusToDosError(L"ntdll.dll", "RtlNtStatusToDosError");
+
+  MOZ_ASSERT(!!pRtlNtStatusToDosError);
+  if (!pRtlNtStatusToDosError) {
+    return ERROR_GEN_FAILURE;
+  }
+
+  return pRtlNtStatusToDosError(aNtStatus);
+}
+
+namespace mozilla {
+
+MFBT_API void* MapRemoteViewOfFile(HANDLE aFileMapping, HANDLE aProcess,
+                                   ULONG64 aOffset, PVOID aBaseAddress,
+                                   SIZE_T aViewSize, ULONG aAllocationType,
+                                   ULONG aProtectionFlags) {
+  static const StaticDynamicallyLinkedFunctionPtr<decltype(&MapViewOfFileNuma2)>
+      pMapViewOfFileNuma2(L"Api-ms-win-core-memory-l1-1-5.dll",
+                          "MapViewOfFileNuma2");
+
+  if (!!pMapViewOfFileNuma2) {
+    return pMapViewOfFileNuma2(aFileMapping, aProcess, aOffset, aBaseAddress,
+                               aViewSize, aAllocationType, aProtectionFlags,
+                               NUMA_NO_PREFERRED_NODE);
+  }
+
+  static const StaticDynamicallyLinkedFunctionPtr<decltype(&NtMapViewOfSection)>
+      pNtMapViewOfSection(L"ntdll.dll", "NtMapViewOfSection");
+
+  MOZ_ASSERT(!!pNtMapViewOfSection);
+  if (!pNtMapViewOfSection) {
+    return nullptr;
+  }
+
+  // For the sake of consistency, we only permit the same flags that
+  // MapViewOfFileNuma2 allows
+  if (aAllocationType != 0 && aAllocationType != MEM_RESERVE &&
+      aAllocationType != MEM_LARGE_PAGES) {
+    ::SetLastError(ERROR_INVALID_PARAMETER);
+    return nullptr;
+  }
+
+  NTSTATUS ntStatus;
+
+  LARGE_INTEGER offset;
+  offset.QuadPart = aOffset;
+
+  ntStatus = pNtMapViewOfSection(aFileMapping, aProcess, &aBaseAddress, 0, 0,
+                                 &offset, &aViewSize, ViewUnmap,
+                                 aAllocationType, aProtectionFlags);
+  if (NT_SUCCESS(ntStatus)) {
+    ::SetLastError(ERROR_SUCCESS);
+    return aBaseAddress;
+  }
+
+  ::SetLastError(GetWin32ErrorCode(ntStatus));
+  return nullptr;
+}
+
+MFBT_API bool UnmapRemoteViewOfFile(HANDLE aProcess, PVOID aBaseAddress) {
+  static const StaticDynamicallyLinkedFunctionPtr<decltype(&UnmapViewOfFile2)>
+      pUnmapViewOfFile2(L"kernel32.dll", "UnmapViewOfFile2");
+
+  if (!!pUnmapViewOfFile2) {
+    return !!pUnmapViewOfFile2(aProcess, aBaseAddress, 0);
+  }
+
+  static const StaticDynamicallyLinkedFunctionPtr<
+      decltype(&NtUnmapViewOfSection)>
+      pNtUnmapViewOfSection(L"ntdll.dll", "NtUnmapViewOfSection");
+
+  MOZ_ASSERT(!!pNtUnmapViewOfSection);
+  if (!pNtUnmapViewOfSection) {
+    return false;
+  }
+
+  NTSTATUS ntStatus = pNtUnmapViewOfSection(aProcess, aBaseAddress);
+  ::SetLastError(GetWin32ErrorCode(ntStatus));
+  return NT_SUCCESS(ntStatus);
+}
+
+}  // namespace mozilla