| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| #define LOG_TAG "libhidlmemory" |
| |
| #include <map> |
| #include <mutex> |
| #include <string> |
| |
| #include <AshmemMemory.h> |
| #include <hidlmemory/mapping.h> |
| |
| #include <android-base/logging.h> |
| #include <android/hidl/memory/1.0/IMapper.h> |
| #include <hidl/HidlSupport.h> |
| #include <log/log.h> |
| |
| using android::sp; |
| using android::hidl::memory::V1_0::IMemory; |
| using android::hidl::memory::V1_0::IMapper; |
| |
| namespace android { |
| namespace hardware { |
| |
| static std::map<std::string, sp<IMapper>> gMappersByName; |
| static std::mutex gMutex; |
| static std::once_flag gOnceFlagLog; |
| |
| static sp<IMemory> createAshmemMemory(const hidl_memory& mem) { |
| if (mem.handle()->numFds == 0) { |
| return nullptr; |
| } |
| |
| // If ashmem service runs in 32-bit (size_t is uint32_t) and a 64-bit |
| // client process requests a memory > 2^32 bytes, the size would be |
| // converted to a 32-bit number in mmap. mmap could succeed but the |
| // mapped memory's actual size would be smaller than the reported size. |
| if (mem.size() > SIZE_MAX) { |
| ALOGE("Cannot map %" PRIu64 " bytes of memory because it is too large.", mem.size()); |
| android_errorWriteLog(0x534e4554, "79376389"); |
| return nullptr; |
| } |
| |
| int fd = mem.handle()->data[0]; |
| void* data = mmap(0, mem.size(), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); |
| if (data == MAP_FAILED) { |
| // mmap never maps at address zero without MAP_FIXED, so we can avoid |
| // exposing clients to MAP_FAILED. |
| return nullptr; |
| } |
| |
| return new impl::AshmemMemory(mem, data); |
| } |
| |
| static inline sp<IMapper> getMapperService(const std::string& name) { |
| std::unique_lock<std::mutex> _lock(gMutex); |
| auto iter = gMappersByName.find(name); |
| if (iter != gMappersByName.end()) { |
| return iter->second; |
| } |
| |
| sp<IMapper> mapper = IMapper::getService(name, true /* getStub */); |
| if (mapper != nullptr) { |
| gMappersByName[name] = mapper; |
| } |
| return mapper; |
| } |
| |
| sp<IMemory> mapMemory(const hidl_memory& memory) { |
| |
| sp<IMapper> mapper = getMapperService(memory.name()); |
| |
| if (mapper == nullptr) { |
| if (memory.name() == "ashmem") { |
| std::call_once(gOnceFlagLog, |
| [&]() { LOG(INFO) << "Using libhidlmemory mapper for ashmem."; }); |
| return createAshmemMemory(memory); |
| } else { |
| LOG(ERROR) << "Could not fetch mapper for " << memory.name() << " shared memory"; |
| return nullptr; |
| } |
| } |
| |
| if (mapper->isRemote()) { |
| LOG(ERROR) << "IMapper must be a passthrough service."; |
| return nullptr; |
| } |
| |
| // hidl_memory's size is stored in uint64_t, but mapMemory's mmap will map |
| // size in size_t. If size is over SIZE_MAX, mapMemory could succeed |
| // but the mapped memory's actual size will be smaller than the reported size. |
| if (memory.size() > SIZE_MAX) { |
| LOG(ERROR) << "Cannot map " << memory.size() << " bytes of memory because it is too large."; |
| android_errorWriteLog(0x534e4554, "79376389"); |
| return nullptr; |
| } |
| |
| Return<sp<IMemory>> ret = mapper->mapMemory(memory); |
| |
| if (!ret.isOk()) { |
| LOG(ERROR) << "hidl_memory map returned transport error."; |
| return nullptr; |
| } |
| |
| return ret; |
| } |
| |
| } // namespace hardware |
| } // namespace android |