Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2018 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 <errno.h> |
| 18 | #include <sys/mman.h> |
| 19 | |
| 20 | #include <cutils/ashmem.h> |
| 21 | #include <log/log.h> |
Jiwen 'Steve' Cai | 8f51ec6 | 2018-08-07 21:50:51 -0700 | [diff] [blame] | 22 | #include <ui/BufferHubMetadata.h> |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 23 | |
| 24 | namespace android { |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 25 | |
| 26 | namespace { |
| 27 | |
| 28 | static const int kAshmemProt = PROT_READ | PROT_WRITE; |
| 29 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 30 | } // namespace |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 31 | |
Jiwen 'Steve' Cai | 1850da2 | 2018-10-15 21:29:14 -0700 | [diff] [blame] | 32 | using dvr::BufferHubDefs::kMetadataHeaderSize; |
| 33 | using dvr::BufferHubDefs::MetadataHeader; |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 34 | |
| 35 | /* static */ |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 36 | BufferHubMetadata BufferHubMetadata::Create(size_t userMetadataSize) { |
| 37 | // The size the of metadata buffer is used as the "width" parameter during allocation. Thus it |
| 38 | // cannot overflow uint32_t. |
| 39 | if (userMetadataSize >= (std::numeric_limits<uint32_t>::max() - kMetadataHeaderSize)) { |
| 40 | ALOGE("BufferHubMetadata::Create: metadata size too big: %zu.", userMetadataSize); |
| 41 | return {}; |
| 42 | } |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 43 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 44 | const size_t metadataSize = userMetadataSize + kMetadataHeaderSize; |
| 45 | int fd = ashmem_create_region(/*name=*/"BufferHubMetadata", metadataSize); |
| 46 | if (fd < 0) { |
| 47 | ALOGE("BufferHubMetadata::Create: failed to create ashmem region."); |
| 48 | return {}; |
| 49 | } |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 50 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 51 | // Hand over the ownership of the fd to a pdx::LocalHandle immediately after the successful |
| 52 | // return of ashmem_create_region. The ashmemHandle is going to own the fd and to prevent fd |
| 53 | // leaks during error handling. |
| 54 | pdx::LocalHandle ashmemHandle{fd}; |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 55 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 56 | if (ashmem_set_prot_region(ashmemHandle.Get(), kAshmemProt) != 0) { |
| 57 | ALOGE("BufferHubMetadata::Create: failed to set protect region."); |
| 58 | return {}; |
| 59 | } |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 60 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 61 | return BufferHubMetadata::Import(std::move(ashmemHandle)); |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 62 | } |
| 63 | |
| 64 | /* static */ |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 65 | BufferHubMetadata BufferHubMetadata::Import(pdx::LocalHandle ashmemHandle) { |
| 66 | if (!ashmem_valid(ashmemHandle.Get())) { |
| 67 | ALOGE("BufferHubMetadata::Import: invalid ashmem fd."); |
| 68 | return {}; |
| 69 | } |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 70 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 71 | size_t metadataSize = static_cast<size_t>(ashmem_get_size_region(ashmemHandle.Get())); |
| 72 | size_t userMetadataSize = metadataSize - kMetadataHeaderSize; |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 73 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 74 | // Note that here the buffer state is mapped from shared memory as an atomic object. The |
| 75 | // std::atomic's constructor will not be called so that the original value stored in the memory |
| 76 | // region can be preserved. |
| 77 | auto metadataHeader = static_cast<MetadataHeader*>(mmap(nullptr, metadataSize, kAshmemProt, |
| 78 | MAP_SHARED, ashmemHandle.Get(), |
| 79 | /*offset=*/0)); |
| 80 | if (metadataHeader == nullptr) { |
| 81 | ALOGE("BufferHubMetadata::Import: failed to map region."); |
| 82 | return {}; |
| 83 | } |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 84 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 85 | return BufferHubMetadata(userMetadataSize, std::move(ashmemHandle), metadataHeader); |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 86 | } |
| 87 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 88 | BufferHubMetadata::BufferHubMetadata(size_t userMetadataSize, pdx::LocalHandle ashmemHandle, |
| 89 | MetadataHeader* metadataHeader) |
| 90 | : mUserMetadataSize(userMetadataSize), |
| 91 | mAshmemHandle(std::move(ashmemHandle)), |
| 92 | mMetadataHeader(metadataHeader) {} |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 93 | |
| 94 | BufferHubMetadata::~BufferHubMetadata() { |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 95 | if (mMetadataHeader != nullptr) { |
| 96 | int ret = munmap(mMetadataHeader, metadata_size()); |
| 97 | ALOGE_IF(ret != 0, |
| 98 | "BufferHubMetadata::~BufferHubMetadata: failed to unmap ashmem, error=%d.", errno); |
| 99 | mMetadataHeader = nullptr; |
| 100 | } |
Jiwen 'Steve' Cai | 4e566ed | 2018-09-19 22:41:42 -0700 | [diff] [blame] | 101 | } |
| 102 | |
Jiwen 'Steve' Cai | ff675b7 | 2018-10-09 18:08:29 -0700 | [diff] [blame] | 103 | } // namespace android |