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 #include <cutils/properties.h>
25
26 #ifdef LIBHIDL_TARGET_DEBUGGABLE
27 #include <dirent.h>
28 #include <dlfcn.h>
29 #include <link.h>
30 #include <utils/misc.h>
31 #include <regex>
32
33 extern "C" __attribute__((weak)) void __sanitizer_cov_dump();
34
35 const char kGcovPrefixEnvVar[] = "GCOV_PREFIX";
36 const char kGcovPrefixOverrideEnvVar[] = "GCOV_PREFIX_OVERRIDE";
37 const char kGcovPrefixPath[] = "/data/misc/trace/";
38 const char kSysPropHalCoverage[] = "hal.coverage.enable";
39 #if defined(__LP64__)
40 const char kSysPropInstrumentationPath[] = "hal.instrumentation.lib.path.64";
41 #else
42 const char kSysPropInstrumentationPath[] = "hal.instrumentation.lib.path.32";
43 #endif
44 #endif // LIBHIDL_TARGET_DEBUGGABLE
45
46 namespace android {
47 namespace hardware {
48 namespace details {
49
logAlwaysFatal(const char * message)50 void logAlwaysFatal(const char* message) {
51 LOG(FATAL) << message;
52 }
53
getVndkVersionStr()54 std::string getVndkVersionStr() {
55 static std::string vndkVersion("0");
56 // "0" means the vndkVersion must be initialized with the property value.
57 // Otherwise, return the value.
58 if (vndkVersion == "0") {
59 vndkVersion = android::base::GetProperty("ro.vndk.version", "");
60 if (vndkVersion != "" && vndkVersion != "current") {
61 vndkVersion = "-" + vndkVersion;
62 } else {
63 vndkVersion = "";
64 }
65 }
66 return vndkVersion;
67 }
68
69 // ----------------------------------------------------------------------
70 // HidlInstrumentor implementation.
HidlInstrumentor(const std::string & package,const std::string & interface)71 HidlInstrumentor::HidlInstrumentor(const std::string& package, const std::string& interface)
72 : mEnableInstrumentation(false),
73 mInstrumentationLibPackage(package),
74 mInterfaceName(interface) {
75 #ifdef LIBHIDL_TARGET_DEBUGGABLE
76 configureInstrumentation(false);
77 if (__sanitizer_cov_dump != nullptr) {
78 ::android::add_sysprop_change_callback(
79 []() {
80 bool enableCoverage = property_get_bool(kSysPropHalCoverage, false);
81 if (enableCoverage) {
82 __sanitizer_cov_dump();
83 }
84 },
85 0);
86 }
87 if (property_get_bool("ro.vts.coverage", false)) {
88 const char* prefixOverride = getenv(kGcovPrefixOverrideEnvVar);
89 if (prefixOverride == nullptr || strcmp(prefixOverride, "true") != 0) {
90 const std::string gcovPath = kGcovPrefixPath + std::to_string(getpid());
91 setenv(kGcovPrefixEnvVar, gcovPath.c_str(), true /* overwrite */);
92 }
93 ::android::add_sysprop_change_callback(
94 []() {
95 const bool enableCoverage = property_get_bool(kSysPropHalCoverage, false);
96 if (enableCoverage) {
97 dl_iterate_phdr(
98 [](struct dl_phdr_info* info, size_t /* size */, void* /* data */) {
99 if (strlen(info->dlpi_name) == 0) return 0;
100
101 void* handle = dlopen(info->dlpi_name, RTLD_LAZY);
102 if (handle == nullptr) {
103 LOG(INFO) << "coverage dlopen failed: " << dlerror();
104 return 0;
105 }
106 void (*flush)() = (void (*)())dlsym(handle, "__gcov_flush");
107 if (flush == nullptr) {
108 return 0;
109 }
110 flush();
111 return 0;
112 },
113 nullptr /* data */);
114 }
115 },
116 0 /* priority */);
117 }
118 #endif
119 }
120
~HidlInstrumentor()121 HidlInstrumentor::~HidlInstrumentor() {}
122
configureInstrumentation(bool log)123 void HidlInstrumentor::configureInstrumentation(bool log) {
124 mEnableInstrumentation = property_get_bool("hal.instrumentation.enable", false);
125 if (mEnableInstrumentation) {
126 if (log) {
127 LOG(INFO) << "Enable instrumentation.";
128 }
129 mInstrumentationCallbacks.clear();
130 registerInstrumentationCallbacks(&mInstrumentationCallbacks);
131 } else {
132 if (log) {
133 LOG(INFO) << "Disable instrumentation.";
134 }
135 mInstrumentationCallbacks.clear();
136 }
137 }
138
registerInstrumentationCallbacks(std::vector<InstrumentationCallback> * instrumentationCallbacks)139 void HidlInstrumentor::registerInstrumentationCallbacks(
140 std::vector<InstrumentationCallback> *instrumentationCallbacks) {
141 #ifdef LIBHIDL_TARGET_DEBUGGABLE
142 std::vector<std::string> instrumentationLibPaths;
143 char instrumentationLibPath[PROPERTY_VALUE_MAX];
144 if (property_get(kSysPropInstrumentationPath, instrumentationLibPath, "") > 0) {
145 instrumentationLibPaths.push_back(instrumentationLibPath);
146 } else {
147 static std::string halLibPathVndkSp = android::base::StringPrintf(
148 HAL_LIBRARY_PATH_VNDK_SP_FOR_VERSION, getVndkVersionStr().c_str());
149 #ifndef __ANDROID_VNDK__
150 instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_SYSTEM);
151 #endif
152 instrumentationLibPaths.push_back(halLibPathVndkSp);
153 instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_VENDOR);
154 instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_ODM);
155 }
156
157 for (const auto& path : instrumentationLibPaths) {
158 DIR *dir = opendir(path.c_str());
159 if (dir == nullptr) {
160 LOG(WARNING) << path << " does not exist. ";
161 return;
162 }
163
164 struct dirent *file;
165 while ((file = readdir(dir)) != nullptr) {
166 if (!isInstrumentationLib(file))
167 continue;
168
169 void *handle = dlopen((path + file->d_name).c_str(), RTLD_NOW);
170 char *error;
171 if (handle == nullptr) {
172 LOG(WARNING) << "couldn't load file: " << file->d_name
173 << " error: " << dlerror();
174 continue;
175 }
176
177 dlerror(); /* Clear any existing error */
178
179 using cbFun = void (*)(
180 const InstrumentationEvent,
181 const char *,
182 const char *,
183 const char *,
184 const char *,
185 std::vector<void *> *);
186 std::string package = mInstrumentationLibPackage;
187 for (size_t i = 0; i < package.size(); i++) {
188 if (package[i] == '.') {
189 package[i] = '_';
190 continue;
191 }
192
193 if (package[i] == '@') {
194 package[i] = '_';
195 package.insert(i + 1, "V");
196 continue;
197 }
198 }
199 auto cb = (cbFun)dlsym(handle, ("HIDL_INSTRUMENTATION_FUNCTION_"
200 + package + "_" + mInterfaceName).c_str());
201 if ((error = dlerror()) != nullptr) {
202 LOG(WARNING)
203 << "couldn't find symbol: HIDL_INSTRUMENTATION_FUNCTION_"
204 << package << "_" << mInterfaceName << ", error: " << error;
205 continue;
206 }
207 instrumentationCallbacks->push_back(cb);
208 LOG(INFO) << "Register instrumentation callback from "
209 << file->d_name;
210 }
211 closedir(dir);
212 }
213 #else
214 // No-op for user builds.
215 (void) instrumentationCallbacks;
216 return;
217 #endif
218 }
219
isInstrumentationLib(const dirent * file)220 bool HidlInstrumentor::isInstrumentationLib(const dirent *file) {
221 #ifdef LIBHIDL_TARGET_DEBUGGABLE
222 if (file->d_type != DT_REG) return false;
223 std::cmatch cm;
224 std::regex e("^" + mInstrumentationLibPackage + "(.*).profiler.so$");
225 if (std::regex_match(file->d_name, cm, e)) return true;
226 #else
227 (void) file;
228 #endif
229 return false;
230 }
231
232 } // namespace details
233 } // namespace hardware
234 } // namespace android
235