WebViewFactory.java revision 85844916b8a7cc7f6aabc6c37af7380a4c000bcb
1/* 2 * Copyright (C) 2012 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 17package android.webkit; 18 19import android.app.ActivityManagerInternal; 20import android.app.AppGlobals; 21import android.app.Application; 22import android.content.Context; 23import android.content.pm.ApplicationInfo; 24import android.content.pm.PackageInfo; 25import android.content.pm.PackageManager; 26import android.os.Build; 27import android.os.Process; 28import android.os.RemoteException; 29import android.os.ServiceManager; 30import android.os.StrictMode; 31import android.os.SystemProperties; 32import android.os.Trace; 33import android.text.TextUtils; 34import android.util.AndroidRuntimeException; 35import android.util.Log; 36 37import com.android.server.LocalServices; 38 39import dalvik.system.VMRuntime; 40 41import java.io.File; 42import java.util.Arrays; 43 44/** 45 * Top level factory, used creating all the main WebView implementation classes. 46 * 47 * @hide 48 */ 49public final class WebViewFactory { 50 51 private static final String CHROMIUM_WEBVIEW_FACTORY = 52 "com.android.webview.chromium.WebViewChromiumFactoryProvider"; 53 54 private static final String NULL_WEBVIEW_FACTORY = 55 "com.android.webview.nullwebview.NullWebViewFactoryProvider"; 56 57 private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_32 = 58 "/data/misc/shared_relro/libwebviewchromium32.relro"; 59 private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_64 = 60 "/data/misc/shared_relro/libwebviewchromium64.relro"; 61 62 public static final String CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY = 63 "persist.sys.webview.vmsize"; 64 private static final long CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES = 100 * 1024 * 1024; 65 66 private static final String LOGTAG = "WebViewFactory"; 67 68 private static final boolean DEBUG = false; 69 70 // Cache the factory both for efficiency, and ensure any one process gets all webviews from the 71 // same provider. 72 private static WebViewFactoryProvider sProviderInstance; 73 private static final Object sProviderLock = new Object(); 74 private static boolean sAddressSpaceReserved = false; 75 private static PackageInfo sPackageInfo; 76 77 public static String getWebViewPackageName() { 78 return AppGlobals.getInitialApplication().getString( 79 com.android.internal.R.string.config_webViewPackageName); 80 } 81 82 public static PackageInfo getLoadedPackageInfo() { 83 return sPackageInfo; 84 } 85 86 static WebViewFactoryProvider getProvider() { 87 synchronized (sProviderLock) { 88 // For now the main purpose of this function (and the factory abstraction) is to keep 89 // us honest and minimize usage of WebView internals when binding the proxy. 90 if (sProviderInstance != null) return sProviderInstance; 91 92 final int uid = android.os.Process.myUid(); 93 if (uid == android.os.Process.ROOT_UID || uid == android.os.Process.SYSTEM_UID) { 94 throw new UnsupportedOperationException( 95 "For security reasons, WebView is not allowed in privileged processes"); 96 } 97 98 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "WebViewFactory.getProvider()"); 99 try { 100 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "WebViewFactory.loadNativeLibrary()"); 101 loadNativeLibrary(); 102 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 103 104 Class<WebViewFactoryProvider> providerClass; 105 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "WebViewFactory.getFactoryClass()"); 106 try { 107 providerClass = getFactoryClass(); 108 } catch (ClassNotFoundException e) { 109 Log.e(LOGTAG, "error loading provider", e); 110 throw new AndroidRuntimeException(e); 111 } finally { 112 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 113 } 114 115 StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads(); 116 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "providerClass.newInstance()"); 117 try { 118 try { 119 sProviderInstance = providerClass.getConstructor(WebViewDelegate.class) 120 .newInstance(new WebViewDelegate()); 121 } catch (Exception e) { 122 sProviderInstance = providerClass.newInstance(); 123 } 124 if (DEBUG) Log.v(LOGTAG, "Loaded provider: " + sProviderInstance); 125 return sProviderInstance; 126 } catch (Exception e) { 127 Log.e(LOGTAG, "error instantiating provider", e); 128 throw new AndroidRuntimeException(e); 129 } finally { 130 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 131 StrictMode.setThreadPolicy(oldPolicy); 132 } 133 } finally { 134 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 135 } 136 } 137 } 138 139 private static Class<WebViewFactoryProvider> getFactoryClass() throws ClassNotFoundException { 140 Application initialApplication = AppGlobals.getInitialApplication(); 141 try { 142 // First fetch the package info so we can log the webview package version. 143 String packageName = getWebViewPackageName(); 144 sPackageInfo = initialApplication.getPackageManager().getPackageInfo(packageName, 0); 145 Log.i(LOGTAG, "Loading " + packageName + " version " + sPackageInfo.versionName + 146 " (code " + sPackageInfo.versionCode + ")"); 147 148 // Construct a package context to load the Java code into the current app. 149 Context webViewContext = initialApplication.createPackageContext(packageName, 150 Context.CONTEXT_INCLUDE_CODE | Context.CONTEXT_IGNORE_SECURITY); 151 initialApplication.getAssets().addAssetPath( 152 webViewContext.getApplicationInfo().sourceDir); 153 ClassLoader clazzLoader = webViewContext.getClassLoader(); 154 Trace.traceBegin(Trace.TRACE_TAG_WEBVIEW, "Class.forName()"); 155 try { 156 return (Class<WebViewFactoryProvider>) Class.forName(CHROMIUM_WEBVIEW_FACTORY, true, 157 clazzLoader); 158 } finally { 159 Trace.traceEnd(Trace.TRACE_TAG_WEBVIEW); 160 } 161 } catch (PackageManager.NameNotFoundException e) { 162 // If the package doesn't exist, then try loading the null WebView instead. 163 // If that succeeds, then this is a device without WebView support; if it fails then 164 // swallow the failure, complain that the real WebView is missing and rethrow the 165 // original exception. 166 try { 167 return (Class<WebViewFactoryProvider>) Class.forName(NULL_WEBVIEW_FACTORY); 168 } catch (ClassNotFoundException e2) { 169 // Ignore. 170 } 171 Log.e(LOGTAG, "Chromium WebView package does not exist", e); 172 throw new AndroidRuntimeException(e); 173 } 174 } 175 176 /** 177 * Perform any WebView loading preparations that must happen in the zygote. 178 * Currently, this means allocating address space to load the real JNI library later. 179 */ 180 public static void prepareWebViewInZygote() { 181 try { 182 System.loadLibrary("webviewchromium_loader"); 183 long addressSpaceToReserve = 184 SystemProperties.getLong(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY, 185 CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES); 186 sAddressSpaceReserved = nativeReserveAddressSpace(addressSpaceToReserve); 187 188 if (sAddressSpaceReserved) { 189 if (DEBUG) { 190 Log.v(LOGTAG, "address space reserved: " + addressSpaceToReserve + " bytes"); 191 } 192 } else { 193 Log.e(LOGTAG, "reserving " + addressSpaceToReserve + 194 " bytes of address space failed"); 195 } 196 } catch (Throwable t) { 197 // Log and discard errors at this stage as we must not crash the zygote. 198 Log.e(LOGTAG, "error preparing native loader", t); 199 } 200 } 201 202 /** 203 * Perform any WebView loading preparations that must happen at boot from the system server, 204 * after the package manager has started or after an update to the webview is installed. 205 * This must be called in the system server. 206 * Currently, this means spawning the child processes which will create the relro files. 207 */ 208 public static void prepareWebViewInSystemServer() { 209 String[] nativePaths = null; 210 try { 211 nativePaths = getWebViewNativeLibraryPaths(); 212 } catch (Throwable t) { 213 // Log and discard errors at this stage as we must not crash the system server. 214 Log.e(LOGTAG, "error preparing webview native library", t); 215 } 216 prepareWebViewInSystemServer(nativePaths); 217 } 218 219 private static void prepareWebViewInSystemServer(String[] nativeLibraryPaths) { 220 if (DEBUG) Log.v(LOGTAG, "creating relro files"); 221 222 // We must always trigger createRelRo regardless of the value of nativeLibraryPaths. Any 223 // unexpected values will be handled there to ensure that we trigger notifying any process 224 // waiting on relreo creation. 225 if (Build.SUPPORTED_32_BIT_ABIS.length > 0) { 226 if (DEBUG) Log.v(LOGTAG, "Create 32 bit relro"); 227 createRelroFile(false /* is64Bit */, nativeLibraryPaths); 228 } 229 230 if (Build.SUPPORTED_64_BIT_ABIS.length > 0) { 231 if (DEBUG) Log.v(LOGTAG, "Create 64 bit relro"); 232 createRelroFile(true /* is64Bit */, nativeLibraryPaths); 233 } 234 } 235 236 public static void onWebViewUpdateInstalled() { 237 String[] nativeLibs = null; 238 try { 239 nativeLibs = WebViewFactory.getWebViewNativeLibraryPaths(); 240 if (nativeLibs != null) { 241 long newVmSize = 0L; 242 243 for (String path : nativeLibs) { 244 if (DEBUG) Log.d(LOGTAG, "Checking file size of " + path); 245 if (path == null) continue; 246 File f = new File(path); 247 if (f.exists()) { 248 long length = f.length(); 249 if (length > newVmSize) { 250 newVmSize = length; 251 } 252 } 253 } 254 255 if (DEBUG) { 256 Log.v(LOGTAG, "Based on library size, need " + newVmSize + 257 " bytes of address space."); 258 } 259 // The required memory can be larger than the file on disk (due to .bss), and an 260 // upgraded version of the library will likely be larger, so always attempt to 261 // reserve twice as much as we think to allow for the library to grow during this 262 // boot cycle. 263 newVmSize = Math.max(2 * newVmSize, CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES); 264 Log.d(LOGTAG, "Setting new address space to " + newVmSize); 265 SystemProperties.set(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY, 266 Long.toString(newVmSize)); 267 } 268 } catch (Throwable t) { 269 // Log and discard errors at this stage as we must not crash the system server. 270 Log.e(LOGTAG, "error preparing webview native library", t); 271 } 272 prepareWebViewInSystemServer(nativeLibs); 273 } 274 275 private static String[] getWebViewNativeLibraryPaths() 276 throws PackageManager.NameNotFoundException { 277 final String NATIVE_LIB_FILE_NAME = "libwebviewchromium.so"; 278 279 PackageManager pm = AppGlobals.getInitialApplication().getPackageManager(); 280 ApplicationInfo ai = pm.getApplicationInfo(getWebViewPackageName(), 0); 281 282 String path32; 283 String path64; 284 boolean primaryArchIs64bit = VMRuntime.is64BitAbi(ai.primaryCpuAbi); 285 if (!TextUtils.isEmpty(ai.secondaryCpuAbi)) { 286 // Multi-arch case. 287 if (primaryArchIs64bit) { 288 // Primary arch: 64-bit, secondary: 32-bit. 289 path64 = ai.nativeLibraryDir; 290 path32 = ai.secondaryNativeLibraryDir; 291 } else { 292 // Primary arch: 32-bit, secondary: 64-bit. 293 path64 = ai.secondaryNativeLibraryDir; 294 path32 = ai.nativeLibraryDir; 295 } 296 } else if (primaryArchIs64bit) { 297 // Single-arch 64-bit. 298 path64 = ai.nativeLibraryDir; 299 path32 = ""; 300 } else { 301 // Single-arch 32-bit. 302 path32 = ai.nativeLibraryDir; 303 path64 = ""; 304 } 305 if (!TextUtils.isEmpty(path32)) path32 += "/" + NATIVE_LIB_FILE_NAME; 306 if (!TextUtils.isEmpty(path64)) path64 += "/" + NATIVE_LIB_FILE_NAME; 307 return new String[] { path32, path64 }; 308 } 309 310 private static void createRelroFile(final boolean is64Bit, String[] nativeLibraryPaths) { 311 final String abi = 312 is64Bit ? Build.SUPPORTED_64_BIT_ABIS[0] : Build.SUPPORTED_32_BIT_ABIS[0]; 313 314 // crashHandler is invoked by the ActivityManagerService when the isolated process crashes. 315 Runnable crashHandler = new Runnable() { 316 @Override 317 public void run() { 318 try { 319 Log.e(LOGTAG, "relro file creator for " + abi + " crashed. Proceeding without"); 320 getUpdateService().notifyRelroCreationCompleted(is64Bit, false); 321 } catch (RemoteException e) { 322 Log.e(LOGTAG, "Cannot reach WebViewUpdateService. " + e.getMessage()); 323 } 324 } 325 }; 326 327 try { 328 if (nativeLibraryPaths == null 329 || nativeLibraryPaths[0] == null || nativeLibraryPaths[1] == null) { 330 throw new IllegalArgumentException( 331 "Native library paths to the WebView RelRo process must not be null!"); 332 } 333 int pid = LocalServices.getService(ActivityManagerInternal.class).startIsolatedProcess( 334 RelroFileCreator.class.getName(), nativeLibraryPaths, "WebViewLoader-" + abi, abi, 335 Process.SHARED_RELRO_UID, crashHandler); 336 if (pid <= 0) throw new Exception("Failed to start the relro file creator process"); 337 } catch (Throwable t) { 338 // Log and discard errors as we must not crash the system server. 339 Log.e(LOGTAG, "error starting relro file creator for abi " + abi, t); 340 crashHandler.run(); 341 } 342 } 343 344 private static class RelroFileCreator { 345 // Called in an unprivileged child process to create the relro file. 346 public static void main(String[] args) { 347 boolean result = false; 348 boolean is64Bit = VMRuntime.getRuntime().is64Bit(); 349 try{ 350 if (args.length != 2 || args[0] == null || args[1] == null) { 351 Log.e(LOGTAG, "Invalid RelroFileCreator args: " + Arrays.toString(args)); 352 return; 353 } 354 Log.v(LOGTAG, "RelroFileCreator (64bit = " + is64Bit + "), " + 355 " 32-bit lib: " + args[0] + ", 64-bit lib: " + args[1]); 356 if (!sAddressSpaceReserved) { 357 Log.e(LOGTAG, "can't create relro file; address space not reserved"); 358 return; 359 } 360 result = nativeCreateRelroFile(args[0] /* path32 */, 361 args[1] /* path64 */, 362 CHROMIUM_WEBVIEW_NATIVE_RELRO_32, 363 CHROMIUM_WEBVIEW_NATIVE_RELRO_64); 364 if (result && DEBUG) Log.v(LOGTAG, "created relro file"); 365 } finally { 366 // We must do our best to always notify the update service, even if something fails. 367 try { 368 getUpdateService().notifyRelroCreationCompleted(is64Bit, result); 369 } catch (RemoteException e) { 370 Log.e(LOGTAG, "error notifying update service", e); 371 } 372 373 if (!result) Log.e(LOGTAG, "failed to create relro file"); 374 375 // Must explicitly exit or else this process will just sit around after we return. 376 System.exit(0); 377 } 378 } 379 } 380 381 private static void loadNativeLibrary() { 382 if (!sAddressSpaceReserved) { 383 Log.e(LOGTAG, "can't load with relro file; address space not reserved"); 384 return; 385 } 386 387 try { 388 getUpdateService().waitForRelroCreationCompleted(VMRuntime.getRuntime().is64Bit()); 389 } catch (RemoteException e) { 390 Log.e(LOGTAG, "error waiting for relro creation, proceeding without", e); 391 return; 392 } 393 394 try { 395 String[] args = getWebViewNativeLibraryPaths(); 396 boolean result = nativeLoadWithRelroFile(args[0] /* path32 */, 397 args[1] /* path64 */, 398 CHROMIUM_WEBVIEW_NATIVE_RELRO_32, 399 CHROMIUM_WEBVIEW_NATIVE_RELRO_64); 400 if (!result) { 401 Log.w(LOGTAG, "failed to load with relro file, proceeding without"); 402 } else if (DEBUG) { 403 Log.v(LOGTAG, "loaded with relro file"); 404 } 405 } catch (PackageManager.NameNotFoundException e) { 406 Log.e(LOGTAG, "Failed to list WebView package libraries for loadNativeLibrary", e); 407 } 408 } 409 410 private static IWebViewUpdateService getUpdateService() { 411 return IWebViewUpdateService.Stub.asInterface(ServiceManager.getService("webviewupdate")); 412 } 413 414 private static native boolean nativeReserveAddressSpace(long addressSpaceToReserve); 415 private static native boolean nativeCreateRelroFile(String lib32, String lib64, 416 String relro32, String relro64); 417 private static native boolean nativeLoadWithRelroFile(String lib32, String lib64, 418 String relro32, String relro64); 419} 420