1 /*
2 * Copyright (C) 2021 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 #define LOG_TAG "LargeParcelable"
18
19 #include "SharedMemory.h"
20
21 #include "MappedFile.h"
22
23 #include <android-base/unique_fd.h>
24 #include <cutils/ashmem.h>
25 #include <utils/Errors.h>
26 #include <utils/Log.h>
27
28 #include <assert.h>
29 #include <errno.h>
30 #include <sys/mman.h>
31
32 #include <memory>
33
34 namespace android {
35 namespace automotive {
36 namespace car_binder_lib {
37
38 using ::android::OK;
39 using ::android::status_t;
40 using ::android::base::borrowed_fd;
41 using ::android::base::unique_fd;
42
SharedMemory(unique_fd fd)43 SharedMemory::SharedMemory(unique_fd fd) : mBorrowedFd(-1), mOwned(true) {
44 int intFd = fd.get();
45 if (!ashmem_valid(intFd)) {
46 ALOGE("%s", "the FD is not valid");
47 mErrno = errno;
48 return;
49 }
50 int size = ashmem_get_size_region(intFd);
51 if (size < 0) {
52 ALOGE("ashmem_get_size_region failed, error: %s", std::strerror(errno));
53 mErrno = errno;
54 return;
55 }
56 mOwnedFd = std::move(fd);
57 mSize = size;
58 }
59
SharedMemory(borrowed_fd fd)60 SharedMemory::SharedMemory(borrowed_fd fd) : mBorrowedFd(-1), mOwned(false) {
61 int intFd = fd.get();
62 if (!ashmem_valid(intFd)) {
63 ALOGE("%s", "the FD is not valid");
64 return;
65 }
66 int size = ashmem_get_size_region(intFd);
67 if (size < 0) {
68 ALOGE("ashmem_get_size_region failed, error: %s", std::strerror(errno));
69 mErrno = errno;
70 return;
71 }
72 mBorrowedFd = std::move(fd);
73 mSize = size;
74 }
75
SharedMemory(size_t size)76 SharedMemory::SharedMemory(size_t size) : mBorrowedFd(-1), mOwned(true) {
77 int fd = ashmem_create_region("SharedMemory", size);
78 if (fd < 0) {
79 ALOGE("ASharedMemory_create failed, error: %s", std::strerror(errno));
80 mErrno = errno;
81 return;
82 }
83 mOwnedFd.reset(fd);
84 mSize = size;
85 }
86
lock()87 status_t SharedMemory::lock() {
88 int result = ashmem_set_prot_region(getFd(), PROT_READ);
89 if (result != 0) {
90 ALOGE("ASharedMemory_setProt failed, error: %s", std::strerror(errno));
91 mErrno = errno;
92 return -result;
93 }
94 mLocked = true;
95 return OK;
96 }
97
98 } // namespace car_binder_lib
99 } // namespace automotive
100 } // namespace android
101