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