1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "AshmemMapper.h"
18
19 #include <sys/mman.h>
20
21 #include "AshmemMemory.h"
22
23 namespace android {
24 namespace hidl {
25 namespace memory {
26 namespace V1_0 {
27 namespace implementation {
28
29 // Methods from ::android::hidl::memory::V1_0::IMapper follow.
mapMemory(const hidl_memory & mem)30 Return<sp<IMemory>> AshmemMapper::mapMemory(const hidl_memory& mem) {
31 if (mem.handle()->numFds == 0) {
32 return nullptr;
33 }
34
35 int fd = mem.handle()->data[0];
36 void* data = mmap(0, mem.size(), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
37 if (data == MAP_FAILED) {
38 // mmap never maps at address zero without MAP_FIXED, so we can avoid
39 // exposing clients to MAP_FAILED.
40 return nullptr;
41 }
42
43 return new AshmemMemory(mem, data);
44 }
45
46 } // namespace implementation
47 } // namespace V1_0
48 } // namespace memory
49 } // namespace hidl
50 } // namespace android
51