1/* 2 * Main entry of app process. 3 * 4 * Starts the interpreted runtime, then starts up the application. 5 * 6 */ 7 8#define LOG_TAG "appproc" 9 10#include <stdio.h> 11#include <stdlib.h> 12#include <sys/prctl.h> 13#include <sys/stat.h> 14#include <unistd.h> 15 16#include <binder/IPCThreadState.h> 17#include <hwbinder/IPCThreadState.h> 18#include <utils/Log.h> 19#include <cutils/memory.h> 20#include <cutils/properties.h> 21#include <cutils/trace.h> 22#include <android_runtime/AndroidRuntime.h> 23#include <private/android_filesystem_config.h> // for AID_SYSTEM 24 25namespace android { 26 27static void app_usage() 28{ 29 fprintf(stderr, 30 "Usage: app_process [java-options] cmd-dir start-class-name [options]\n"); 31} 32 33class AppRuntime : public AndroidRuntime 34{ 35public: 36 AppRuntime(char* argBlockStart, const size_t argBlockLength) 37 : AndroidRuntime(argBlockStart, argBlockLength) 38 , mClass(NULL) 39 { 40 } 41 42 void setClassNameAndArgs(const String8& className, int argc, char * const *argv) { 43 mClassName = className; 44 for (int i = 0; i < argc; ++i) { 45 mArgs.add(String8(argv[i])); 46 } 47 } 48 49 virtual void onVmCreated(JNIEnv* env) 50 { 51 if (mClassName.isEmpty()) { 52 return; // Zygote. Nothing to do here. 53 } 54 55 /* 56 * This is a little awkward because the JNI FindClass call uses the 57 * class loader associated with the native method we're executing in. 58 * If called in onStarted (from RuntimeInit.finishInit because we're 59 * launching "am", for example), FindClass would see that we're calling 60 * from a boot class' native method, and so wouldn't look for the class 61 * we're trying to look up in CLASSPATH. Unfortunately it needs to, 62 * because the "am" classes are not boot classes. 63 * 64 * The easiest fix is to call FindClass here, early on before we start 65 * executing boot class Java code and thereby deny ourselves access to 66 * non-boot classes. 67 */ 68 char* slashClassName = toSlashClassName(mClassName.string()); 69 mClass = env->FindClass(slashClassName); 70 if (mClass == NULL) { 71 ALOGE("ERROR: could not find class '%s'\n", mClassName.string()); 72 } 73 free(slashClassName); 74 75 mClass = reinterpret_cast<jclass>(env->NewGlobalRef(mClass)); 76 } 77 78 virtual void onStarted() 79 { 80 sp<ProcessState> proc = ProcessState::self(); 81 ALOGV("App process: starting thread pool.\n"); 82 proc->startThreadPool(); 83 84 AndroidRuntime* ar = AndroidRuntime::getRuntime(); 85 ar->callMain(mClassName, mClass, mArgs); 86 87 IPCThreadState::self()->stopProcess(); 88 hardware::IPCThreadState::self()->stopProcess(); 89 } 90 91 virtual void onZygoteInit() 92 { 93 sp<ProcessState> proc = ProcessState::self(); 94 ALOGV("App process: starting thread pool.\n"); 95 proc->startThreadPool(); 96 } 97 98 virtual void onExit(int code) 99 { 100 if (mClassName.isEmpty()) { 101 // if zygote 102 IPCThreadState::self()->stopProcess(); 103 hardware::IPCThreadState::self()->stopProcess(); 104 } 105 106 AndroidRuntime::onExit(code); 107 } 108 109 110 String8 mClassName; 111 Vector<String8> mArgs; 112 jclass mClass; 113}; 114 115} 116 117using namespace android; 118 119static size_t computeArgBlockSize(int argc, char* const argv[]) { 120 // TODO: This assumes that all arguments are allocated in 121 // contiguous memory. There isn't any documented guarantee 122 // that this is the case, but this is how the kernel does it 123 // (see fs/exec.c). 124 // 125 // Also note that this is a constant for "normal" android apps. 126 // Since they're forked from zygote, the size of their command line 127 // is the size of the zygote command line. 128 // 129 // We change the process name of the process by over-writing 130 // the start of the argument block (argv[0]) with the new name of 131 // the process, so we'd mysteriously start getting truncated process 132 // names if the zygote command line decreases in size. 133 uintptr_t start = reinterpret_cast<uintptr_t>(argv[0]); 134 uintptr_t end = reinterpret_cast<uintptr_t>(argv[argc - 1]); 135 end += strlen(argv[argc - 1]) + 1; 136 return (end - start); 137} 138 139static void maybeCreateDalvikCache() { 140#if defined(__aarch64__) 141 static const char kInstructionSet[] = "arm64"; 142#elif defined(__x86_64__) 143 static const char kInstructionSet[] = "x86_64"; 144#elif defined(__arm__) 145 static const char kInstructionSet[] = "arm"; 146#elif defined(__i386__) 147 static const char kInstructionSet[] = "x86"; 148#elif defined (__mips__) && !defined(__LP64__) 149 static const char kInstructionSet[] = "mips"; 150#elif defined (__mips__) && defined(__LP64__) 151 static const char kInstructionSet[] = "mips64"; 152#else 153#error "Unknown instruction set" 154#endif 155 const char* androidRoot = getenv("ANDROID_DATA"); 156 LOG_ALWAYS_FATAL_IF(androidRoot == NULL, "ANDROID_DATA environment variable unset"); 157 158 char dalvikCacheDir[PATH_MAX]; 159 const int numChars = snprintf(dalvikCacheDir, PATH_MAX, 160 "%s/dalvik-cache/%s", androidRoot, kInstructionSet); 161 LOG_ALWAYS_FATAL_IF((numChars >= PATH_MAX || numChars < 0), 162 "Error constructing dalvik cache : %s", strerror(errno)); 163 164 int result = mkdir(dalvikCacheDir, 0711); 165 LOG_ALWAYS_FATAL_IF((result < 0 && errno != EEXIST), 166 "Error creating cache dir %s : %s", dalvikCacheDir, strerror(errno)); 167 168 // We always perform these steps because the directory might 169 // already exist, with wider permissions and a different owner 170 // than we'd like. 171 result = chown(dalvikCacheDir, AID_ROOT, AID_ROOT); 172 LOG_ALWAYS_FATAL_IF((result < 0), "Error changing dalvik-cache ownership : %s", strerror(errno)); 173 174 result = chmod(dalvikCacheDir, 0711); 175 LOG_ALWAYS_FATAL_IF((result < 0), 176 "Error changing dalvik-cache permissions : %s", strerror(errno)); 177} 178 179#if defined(__LP64__) 180static const char ABI_LIST_PROPERTY[] = "ro.product.cpu.abilist64"; 181static const char ZYGOTE_NICE_NAME[] = "zygote64"; 182#else 183static const char ABI_LIST_PROPERTY[] = "ro.product.cpu.abilist32"; 184static const char ZYGOTE_NICE_NAME[] = "zygote"; 185#endif 186 187int main(int argc, char* const argv[]) 188{ 189 if (!LOG_NDEBUG) { 190 String8 argv_String; 191 for (int i = 0; i < argc; ++i) { 192 argv_String.append("\""); 193 argv_String.append(argv[i]); 194 argv_String.append("\" "); 195 } 196 ALOGV("app_process main with argv: %s", argv_String.string()); 197 } 198 199 AppRuntime runtime(argv[0], computeArgBlockSize(argc, argv)); 200 // Process command line arguments 201 // ignore argv[0] 202 argc--; 203 argv++; 204 205 // Everything up to '--' or first non '-' arg goes to the vm. 206 // 207 // The first argument after the VM args is the "parent dir", which 208 // is currently unused. 209 // 210 // After the parent dir, we expect one or more the following internal 211 // arguments : 212 // 213 // --zygote : Start in zygote mode 214 // --start-system-server : Start the system server. 215 // --application : Start in application (stand alone, non zygote) mode. 216 // --nice-name : The nice name for this process. 217 // 218 // For non zygote starts, these arguments will be followed by 219 // the main class name. All remaining arguments are passed to 220 // the main method of this class. 221 // 222 // For zygote starts, all remaining arguments are passed to the zygote. 223 // main function. 224 // 225 // Note that we must copy argument string values since we will rewrite the 226 // entire argument block when we apply the nice name to argv0. 227 // 228 // As an exception to the above rule, anything in "spaced commands" 229 // goes to the vm even though it has a space in it. 230 const char* spaced_commands[] = { "-cp", "-classpath" }; 231 // Allow "spaced commands" to be succeeded by exactly 1 argument (regardless of -s). 232 bool known_command = false; 233 234 int i; 235 for (i = 0; i < argc; i++) { 236 if (known_command == true) { 237 runtime.addOption(strdup(argv[i])); 238 // The static analyzer gets upset that we don't ever free the above 239 // string. Since the allocation is from main, leaking it doesn't seem 240 // problematic. NOLINTNEXTLINE 241 ALOGV("app_process main add known option '%s'", argv[i]); 242 known_command = false; 243 continue; 244 } 245 246 for (int j = 0; 247 j < static_cast<int>(sizeof(spaced_commands) / sizeof(spaced_commands[0])); 248 ++j) { 249 if (strcmp(argv[i], spaced_commands[j]) == 0) { 250 known_command = true; 251 ALOGV("app_process main found known command '%s'", argv[i]); 252 } 253 } 254 255 if (argv[i][0] != '-') { 256 break; 257 } 258 if (argv[i][1] == '-' && argv[i][2] == 0) { 259 ++i; // Skip --. 260 break; 261 } 262 263 runtime.addOption(strdup(argv[i])); 264 // The static analyzer gets upset that we don't ever free the above 265 // string. Since the allocation is from main, leaking it doesn't seem 266 // problematic. NOLINTNEXTLINE 267 ALOGV("app_process main add option '%s'", argv[i]); 268 } 269 270 // Parse runtime arguments. Stop at first unrecognized option. 271 bool zygote = false; 272 bool startSystemServer = false; 273 bool application = false; 274 String8 niceName; 275 String8 className; 276 277 ++i; // Skip unused "parent dir" argument. 278 while (i < argc) { 279 const char* arg = argv[i++]; 280 if (strcmp(arg, "--zygote") == 0) { 281 zygote = true; 282 niceName = ZYGOTE_NICE_NAME; 283 } else if (strcmp(arg, "--start-system-server") == 0) { 284 startSystemServer = true; 285 } else if (strcmp(arg, "--application") == 0) { 286 application = true; 287 } else if (strncmp(arg, "--nice-name=", 12) == 0) { 288 niceName.setTo(arg + 12); 289 } else if (strncmp(arg, "--", 2) != 0) { 290 className.setTo(arg); 291 break; 292 } else { 293 --i; 294 break; 295 } 296 } 297 298 Vector<String8> args; 299 if (!className.isEmpty()) { 300 // We're not in zygote mode, the only argument we need to pass 301 // to RuntimeInit is the application argument. 302 // 303 // The Remainder of args get passed to startup class main(). Make 304 // copies of them before we overwrite them with the process name. 305 args.add(application ? String8("application") : String8("tool")); 306 runtime.setClassNameAndArgs(className, argc - i, argv + i); 307 308 if (!LOG_NDEBUG) { 309 String8 restOfArgs; 310 char* const* argv_new = argv + i; 311 int argc_new = argc - i; 312 for (int k = 0; k < argc_new; ++k) { 313 restOfArgs.append("\""); 314 restOfArgs.append(argv_new[k]); 315 restOfArgs.append("\" "); 316 } 317 ALOGV("Class name = %s, args = %s", className.string(), restOfArgs.string()); 318 } 319 } else { 320 // We're in zygote mode. 321 maybeCreateDalvikCache(); 322 323 if (startSystemServer) { 324 args.add(String8("start-system-server")); 325 } 326 327 char prop[PROP_VALUE_MAX]; 328 if (property_get(ABI_LIST_PROPERTY, prop, NULL) == 0) { 329 LOG_ALWAYS_FATAL("app_process: Unable to determine ABI list from property %s.", 330 ABI_LIST_PROPERTY); 331 return 11; 332 } 333 334 String8 abiFlag("--abi-list="); 335 abiFlag.append(prop); 336 args.add(abiFlag); 337 338 // In zygote mode, pass all remaining arguments to the zygote 339 // main() method. 340 for (; i < argc; ++i) { 341 args.add(String8(argv[i])); 342 } 343 } 344 345 if (!niceName.isEmpty()) { 346 runtime.setArgv0(niceName.string(), true /* setProcName */); 347 } 348 349 if (zygote) { 350 runtime.start("com.android.internal.os.ZygoteInit", args, zygote); 351 } else if (className) { 352 runtime.start("com.android.internal.os.RuntimeInit", args, zygote); 353 } else { 354 fprintf(stderr, "Error: no class name or --zygote supplied.\n"); 355 app_usage(); 356 LOG_ALWAYS_FATAL("app_process: no class name or --zygote supplied."); 357 } 358} 359