Initial in-process implementation of some Mojo primitives.

mojo/system/memory.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MOJO_SYSTEM_MEMORY_H_
+#define MOJO_SYSTEM_MEMORY_H_
+
+#include <stddef.h>
+
+namespace mojo {
+namespace system {
+
+// Verify that |count * size_each| bytes can be read from the user |pointer|
+// insofar as possible/necessary. |count| and |size_each| are specified
+// separately instead of a single size, since |count * size_each| may overflow a
+// |size_t|. |count| may be zero but |size_each| must be nonzero.
+//
+// For example, if running in kernel mode, this should be a full verification
+// that the given memory is owned and readable by the user process. In user
+// mode, if crashes are acceptable, this may do nothing at all (and always
+// return true).
+bool VerifyUserPointer(const void* pointer, size_t count, size_t size_each);
+
+}  // namespace system
+}  // namespace mojo
+
+#endif  // MOJO_SYSTEM_MEMORY_H_