| // 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. |
| |
| #include "mojo/edk/system/memory.h" |
| |
| #include <limits> |
| |
| #include "base/logging.h" |
| #include "build/build_config.h" |
| |
| namespace mojo { |
| namespace system { |
| namespace internal { |
| |
| template <size_t alignment> |
| bool IsAligned(const void* pointer) { |
| return reinterpret_cast<uintptr_t>(pointer) % alignment == 0; |
| } |
| |
| // MSVS (2010, 2013) sometimes (on the stack) aligns, e.g., |int64_t|s (for |
| // which |__alignof(int64_t)| is 8) to 4-byte boundaries. http://goo.gl/Y2n56T |
| #if defined(COMPILER_MSVC) && defined(ARCH_CPU_32_BITS) |
| template <> |
| bool IsAligned<8>(const void* pointer) { |
| return reinterpret_cast<uintptr_t>(pointer) % 4 == 0; |
| } |
| #endif |
| |
| template <size_t size, size_t alignment> |
| void MOJO_SYSTEM_IMPL_EXPORT CheckUserPointer(const void* pointer) { |
| CHECK(pointer && IsAligned<alignment>(pointer)); |
| } |
| |
| // Explicitly instantiate the sizes we need. Add instantiations as needed. |
| template void MOJO_SYSTEM_IMPL_EXPORT CheckUserPointer<1, 1>(const void*); |
| template void MOJO_SYSTEM_IMPL_EXPORT CheckUserPointer<4, 4>(const void*); |
| template void MOJO_SYSTEM_IMPL_EXPORT CheckUserPointer<8, 4>(const void*); |
| template void MOJO_SYSTEM_IMPL_EXPORT CheckUserPointer<8, 8>(const void*); |
| |
| template <size_t size, size_t alignment> |
| void MOJO_SYSTEM_IMPL_EXPORT |
| CheckUserPointerWithCount(const void* pointer, size_t count) { |
| CHECK_LE(count, std::numeric_limits<size_t>::max() / size); |
| CHECK(count == 0 || (pointer && IsAligned<alignment>(pointer))); |
| } |
| |
| // Explicitly instantiate the sizes we need. Add instantiations as needed. |
| template void MOJO_SYSTEM_IMPL_EXPORT |
| CheckUserPointerWithCount<1, 1>(const void*, size_t); |
| template void MOJO_SYSTEM_IMPL_EXPORT |
| CheckUserPointerWithCount<4, 4>(const void*, size_t); |
| template void MOJO_SYSTEM_IMPL_EXPORT |
| CheckUserPointerWithCount<8, 4>(const void*, size_t); |
| template void MOJO_SYSTEM_IMPL_EXPORT |
| CheckUserPointerWithCount<8, 8>(const void*, size_t); |
| |
| template <size_t alignment> |
| void CheckUserPointerWithSize(const void* pointer, size_t size) { |
| // TODO(vtl): If running in kernel mode, do a full verification. For now, just |
| // check that it's non-null and aligned. (A faster user mode implementation is |
| // also possible if this check is skipped.) |
| CHECK(size == 0 || (!!pointer && internal::IsAligned<alignment>(pointer))); |
| } |
| |
| // Explicitly instantiate the sizes we need. Add instantiations as needed. |
| template void MOJO_SYSTEM_IMPL_EXPORT |
| CheckUserPointerWithSize<1>(const void*, size_t); |
| template void MOJO_SYSTEM_IMPL_EXPORT |
| CheckUserPointerWithSize<4>(const void*, size_t); |
| // Whereas the other |Check...()| functions are usually used with integral typs |
| // or arrays of integral types, this one is used with Options structs for which |
| // alignment has been explicitly been specified (using |MOJO_ALIGNAS()|), which |
| // MSVS *does* respect. |
| #if defined(COMPILER_MSVC) && defined(ARCH_CPU_32_BITS) |
| template <> |
| void MOJO_SYSTEM_IMPL_EXPORT |
| CheckUserPointerWithSize<8>(const void* pointer, size_t size) { |
| CHECK(size == 0 || |
| (!!pointer && reinterpret_cast<uintptr_t>(pointer) % 8 == 0)); |
| } |
| #else |
| template void MOJO_SYSTEM_IMPL_EXPORT |
| CheckUserPointerWithSize<8>(const void*, size_t); |
| #endif |
| |
| } // namespace internal |
| } // namespace system |
| } // namespace mojo |