Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 56 insertions, 0 deletions

diff --git a/ipc/glue/ByteBufUtils.h b/ipc/glue/ByteBufUtils.h
new file mode 100644
index 0000000000..ba19864214
--- /dev/null
+++ b/ipc/glue/ByteBufUtils.h
@@ -0,0 +1,56 @@
+/* -*- 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/. */
+
+/* A type that can be sent without needing to make a copy during
+ * serialization. In addition the receiver can take ownership of the
+ * data to avoid having to make an additional copy. */
+
+#ifndef mozilla_ipc_ByteBufUtils_h
+#define mozilla_ipc_ByteBufUtils_h
+
+#include "mozilla/ipc/ByteBuf.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/mozalloc_oom.h"
+#include "ipc/IPCMessageUtils.h"
+
+namespace IPC {
+
+template <>
+struct ParamTraits<mozilla::ipc::ByteBuf> {
+  typedef mozilla::ipc::ByteBuf paramType;
+
+  // this is where we transfer the memory from the ByteBuf to IPDL, avoiding a
+  // copy
+  static void Write(MessageWriter* aWriter, paramType&& aParam) {
+    // We need to send the length as a 32-bit value, not a size_t, because on
+    // ARM64 Windows we end up with a 32-bit GMP process sending a ByteBuf to
+    // a 64-bit parent process. WriteBytesZeroCopy takes a uint32_t as an
+    // argument, so it would end up getting truncated anyways. See bug 1757534.
+    mozilla::CheckedInt<uint32_t> length = aParam.mLen;
+    MOZ_RELEASE_ASSERT(length.isValid());
+    WriteParam(aWriter, length.value());
+    // hand over ownership of the buffer to the Message
+    aWriter->WriteBytesZeroCopy(aParam.mData, length.value(), aParam.mCapacity);
+    aParam.mData = nullptr;
+    aParam.mCapacity = 0;
+    aParam.mLen = 0;
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    // We make a copy from the BufferList so that we get a contigous result.
+    uint32_t length;
+    if (!ReadParam(aReader, &length)) return false;
+    if (!aResult->Allocate(length)) {
+      mozalloc_handle_oom(length);
+      return false;
+    }
+    return aReader->ReadBytesInto(aResult->mData, length);
+  }
+};
+
+}  // namespace IPC
+
+#endif  // ifndef mozilla_ipc_ByteBufUtils_h