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 #define LOG_TAG "HidlInternal"
18
19 #include <hidl/HidlInternal.h>
20
21 #include <android-base/logging.h>
22 #include <android-base/properties.h>
23 #include <android-base/stringprintf.h>
24
25 #ifdef LIBHIDL_TARGET_DEBUGGABLE
26 #include <dirent.h>
27 #include <dlfcn.h>
28 #include <link.h>
29 #include <utils/misc.h>
30 #include <regex>
31
32 extern "C" __attribute__((weak)) void __sanitizer_cov_dump();
33
34 const char kGcovPrefixEnvVar[] = "GCOV_PREFIX";
35 const char kGcovPrefixOverrideEnvVar[] = "GCOV_PREFIX_OVERRIDE";
36 const char kGcovPrefixPath[] = "/data/misc/trace/";
37 const char kSysPropHalCoverage[] = "hal.coverage.enable";
38 #if defined(__LP64__)
39 const char kSysPropInstrumentationPath[] = "hal.instrumentation.lib.path.64";
40 #else
41 const char kSysPropInstrumentationPath[] = "hal.instrumentation.lib.path.32";
42 #endif
43 #endif // LIBHIDL_TARGET_DEBUGGABLE
44
45 namespace android {
46 namespace hardware {
47 namespace details {
48
logAlwaysFatal(const char * message)49 void logAlwaysFatal(const char* message) {
50 LOG(FATAL) << message;
51 }
52
getVndkVersionStr()53 std::string getVndkVersionStr() {
54 static std::string vndkVersion = base::GetProperty("ro.vndk.version", "");
55 return vndkVersion;
56 }
57
58 // ----------------------------------------------------------------------
59 // HidlInstrumentor implementation.
HidlInstrumentor(const std::string & package,const std::string & interface)60 HidlInstrumentor::HidlInstrumentor(const std::string& package, const std::string& interface)
61 : mEnableInstrumentation(false),
62 mInstrumentationLibPackage(package),
63 mInterfaceName(interface) {
64 #ifdef LIBHIDL_TARGET_DEBUGGABLE
65 configureInstrumentation(false);
66 if (__sanitizer_cov_dump != nullptr) {
67 ::android::add_sysprop_change_callback(
68 []() {
69 bool enableCoverage = base::GetBoolProperty(kSysPropHalCoverage, false);
70 if (enableCoverage) {
71 __sanitizer_cov_dump();
72 }
73 },
74 0);
75 }
76 if (base::GetBoolProperty("ro.vts.coverage", false)) {
77 const char* prefixOverride = getenv(kGcovPrefixOverrideEnvVar);
78 if (prefixOverride == nullptr || strcmp(prefixOverride, "true") != 0) {
79 const std::string gcovPath = kGcovPrefixPath + std::to_string(getpid());
80 setenv(kGcovPrefixEnvVar, gcovPath.c_str(), true /* overwrite */);
81 }
82 ::android::add_sysprop_change_callback(
83 []() {
84 const bool enableCoverage = base::GetBoolProperty(kSysPropHalCoverage, false);
85 if (enableCoverage) {
86 dl_iterate_phdr(
87 [](struct dl_phdr_info* info, size_t /* size */, void* /* data */) {
88 if (strlen(info->dlpi_name) == 0) return 0;
89
90 void* handle = dlopen(info->dlpi_name, RTLD_LAZY);
91 if (handle == nullptr) {
92 LOG(INFO) << "coverage dlopen failed: " << dlerror();
93 return 0;
94 }
95 void (*flush)() = (void (*)())dlsym(handle, "__gcov_flush");
96 if (flush == nullptr) {
97 return 0;
98 }
99 flush();
100 return 0;
101 },
102 nullptr /* data */);
103 }
104 },
105 0 /* priority */);
106 }
107 #endif
108 }
109
~HidlInstrumentor()110 HidlInstrumentor::~HidlInstrumentor() {}
111
configureInstrumentation(bool log)112 void HidlInstrumentor::configureInstrumentation(bool log) {
113 mEnableInstrumentation = base::GetBoolProperty("hal.instrumentation.enable", false);
114 if (mEnableInstrumentation) {
115 if (log) {
116 LOG(INFO) << "Enable instrumentation.";
117 }
118 mInstrumentationCallbacks.clear();
119 registerInstrumentationCallbacks(&mInstrumentationCallbacks);
120 } else {
121 if (log) {
122 LOG(INFO) << "Disable instrumentation.";
123 }
124 mInstrumentationCallbacks.clear();
125 }
126 }
127
registerInstrumentationCallbacks(std::vector<InstrumentationCallback> * instrumentationCallbacks)128 void HidlInstrumentor::registerInstrumentationCallbacks(
129 std::vector<InstrumentationCallback> *instrumentationCallbacks) {
130 #ifdef LIBHIDL_TARGET_DEBUGGABLE
131 std::vector<std::string> instrumentationLibPaths;
132 const std::string instrumentationLibPath = base::GetProperty(kSysPropInstrumentationPath, "");
133 if (instrumentationLibPath.size() > 0) {
134 instrumentationLibPaths.push_back(instrumentationLibPath);
135 } else {
136 static std::string halLibPathVndkSp = android::base::StringPrintf(
137 HAL_LIBRARY_PATH_VNDK_SP_FOR_VERSION, getVndkVersionStr().c_str());
138 #ifndef __ANDROID_VNDK__
139 instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_SYSTEM);
140 #endif
141 instrumentationLibPaths.push_back(halLibPathVndkSp);
142 instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_VENDOR);
143 instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_ODM);
144 }
145
146 for (const auto& path : instrumentationLibPaths) {
147 DIR *dir = opendir(path.c_str());
148 if (dir == nullptr) {
149 LOG(WARNING) << path << " does not exist. ";
150 return;
151 }
152
153 struct dirent *file;
154 while ((file = readdir(dir)) != nullptr) {
155 if (!isInstrumentationLib(file))
156 continue;
157
158 void *handle = dlopen((path + file->d_name).c_str(), RTLD_NOW);
159 char *error;
160 if (handle == nullptr) {
161 LOG(WARNING) << "couldn't load file: " << file->d_name
162 << " error: " << dlerror();
163 continue;
164 }
165
166 dlerror(); /* Clear any existing error */
167
168 using cbFun = void (*)(
169 const InstrumentationEvent,
170 const char *,
171 const char *,
172 const char *,
173 const char *,
174 std::vector<void *> *);
175 std::string package = mInstrumentationLibPackage;
176 for (size_t i = 0; i < package.size(); i++) {
177 if (package[i] == '.') {
178 package[i] = '_';
179 continue;
180 }
181
182 if (package[i] == '@') {
183 package[i] = '_';
184 package.insert(i + 1, "V");
185 continue;
186 }
187 }
188 auto cb = (cbFun)dlsym(handle, ("HIDL_INSTRUMENTATION_FUNCTION_"
189 + package + "_" + mInterfaceName).c_str());
190 if ((error = dlerror()) != nullptr) {
191 LOG(WARNING)
192 << "couldn't find symbol: HIDL_INSTRUMENTATION_FUNCTION_"
193 << package << "_" << mInterfaceName << ", error: " << error;
194 continue;
195 }
196 instrumentationCallbacks->push_back(cb);
197 LOG(INFO) << "Register instrumentation callback from "
198 << file->d_name;
199 }
200 closedir(dir);
201 }
202 #else
203 // No-op for user builds.
204 (void) instrumentationCallbacks;
205 return;
206 #endif
207 }
208
isInstrumentationLib(const dirent * file)209 bool HidlInstrumentor::isInstrumentationLib(const dirent *file) {
210 #ifdef LIBHIDL_TARGET_DEBUGGABLE
211 if (file->d_type != DT_REG) return false;
212 std::cmatch cm;
213 std::regex e("^" + mInstrumentationLibPackage + "(.*).profiler.so$");
214 if (std::regex_match(file->d_name, cm, e)) return true;
215 #else
216 (void) file;
217 #endif
218 return false;
219 }
220
221 } // namespace details
222 } // namespace hardware
223 } // namespace android
224