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 #define LOG_TAG "libhidlmemory" 17 18 #include <map> 19 #include <mutex> 20 #include <string> 21 22 #include <hidlmemory/mapping.h> 23 24 #include <android-base/logging.h> 25 #include <android/hidl/memory/1.0/IMapper.h> 26 #include <hidl/HidlSupport.h> 27 #include <log/log.h> 28 29 using android::sp; 30 using android::hidl::memory::V1_0::IMemory; 31 using android::hidl::memory::V1_0::IMapper; 32 33 namespace android { 34 namespace hardware { 35 36 static std::map<std::string, sp<IMapper>> gMappersByName; 37 static std::mutex gMutex; 38 getMapperService(const std::string & name)39static inline sp<IMapper> getMapperService(const std::string& name) { 40 std::unique_lock<std::mutex> _lock(gMutex); 41 auto iter = gMappersByName.find(name); 42 if (iter != gMappersByName.end()) { 43 return iter->second; 44 } 45 46 sp<IMapper> mapper = IMapper::getService(name, true /* getStub */); 47 if (mapper != nullptr) { 48 gMappersByName[name] = mapper; 49 } 50 return mapper; 51 } 52 mapMemory(const hidl_memory & memory)53sp<IMemory> mapMemory(const hidl_memory& memory) { 54 55 sp<IMapper> mapper = getMapperService(memory.name()); 56 57 if (mapper == nullptr) { 58 LOG(ERROR) << "Could not fetch mapper for " << memory.name() << " shared memory"; 59 return nullptr; 60 } 61 62 if (mapper->isRemote()) { 63 LOG(ERROR) << "IMapper must be a passthrough service."; 64 return nullptr; 65 } 66 67 // hidl_memory's size is stored in uint64_t, but mapMemory's mmap will map 68 // size in size_t. If size is over SIZE_MAX, mapMemory could succeed 69 // but the mapped memory's actual size will be smaller than the reported size. 70 if (memory.size() > SIZE_MAX) { 71 LOG(ERROR) << "Cannot map " << memory.size() << " bytes of memory because it is too large."; 72 android_errorWriteLog(0x534e4554, "79376389"); 73 return nullptr; 74 } 75 76 Return<sp<IMemory>> ret = mapper->mapMemory(memory); 77 78 if (!ret.isOk()) { 79 LOG(ERROR) << "hidl_memory map returned transport error."; 80 return nullptr; 81 } 82 83 return ret; 84 } 85 86 } // namespace hardware 87 } // namespace android 88