1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef MOJO_SYSTEM_MEMORY_H_
6 #define MOJO_SYSTEM_MEMORY_H_
10 #include "mojo/public/system/system_export.h"
15 // This is just forward-declared, with the definition and explicit
16 // instantiations in the .cc file. This is used by |VerifyUserPointer<T>()|
17 // below, and you should use that instead.
18 template <size_t size>
19 bool MOJO_SYSTEM_EXPORT VerifyUserPointerForSize(const void* pointer,
22 // Verify that |count * sizeof(T)| bytes can be read from the user |pointer|
23 // insofar as possible/necessary (note: this is done carefully since |count *
24 // sizeof(T)| may overflow a |size_t|. |count| may be zero. If |T| is |void|,
25 // then the size of each element is taken to be a single byte.
27 // For example, if running in kernel mode, this should be a full verification
28 // that the given memory is owned and readable by the user process. In user
29 // mode, if crashes are acceptable, this may do nothing at all (and always
32 bool VerifyUserPointer(const T* pointer, size_t count) {
33 return VerifyUserPointerForSize<sizeof(T)>(pointer, count);
36 // Special-case |T| equals |void| so that the size is in bytes, as indicated
39 inline bool VerifyUserPointer<void>(const void* pointer, size_t count) {
40 return VerifyUserPointerForSize<1>(pointer, count);
46 #endif // MOJO_SYSTEM_MEMORY_H_