core/java/android/webkit/WebViewFactory.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2012 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package android.webkit;

 import android.app.ActivityManagerInternal;
 import android.app.Application;
 import android.app.AppGlobals;
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.os.Build;
 import android.os.Process;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.StrictMode;
 import android.os.SystemProperties;
 import android.text.TextUtils;
 import android.util.AndroidRuntimeException;
 import android.util.Log;
 import com.android.server.LocalServices;
 import dalvik.system.VMRuntime;

 import java.io.File;
 import java.util.Arrays;

 import com.android.internal.os.Zygote;

 /**
  * Top level factory, used creating all the main WebView implementation classes.
  *
  * @hide
  */
 public final class WebViewFactory {

     private static final String CHROMIUM_WEBVIEW_FACTORY =
             "com.android.webview.chromium.WebViewChromiumFactoryProvider";

     private static final String NULL_WEBVIEW_FACTORY =
             "com.android.webview.nullwebview.NullWebViewFactoryProvider";

     private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_32 =
             "/data/misc/shared_relro/libwebviewchromium32.relro";
     private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_64 =
             "/data/misc/shared_relro/libwebviewchromium64.relro";

     public static final String CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY =
             "persist.sys.webview.vmsize";
     private static final long CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES = 100 * 1024 * 1024;

     private static final String LOGTAG = "WebViewFactory";

     private static final boolean DEBUG = false;

     // Cache the factory both for efficiency, and ensure any one process gets all webviews from the
     // same provider.
     private static WebViewFactoryProvider sProviderInstance;
     private static final Object sProviderLock = new Object();
     private static boolean sAddressSpaceReserved = false;

     public static String getWebViewPackageName() {
         return AppGlobals.getInitialApplication().getString(
                 com.android.internal.R.string.config_webViewPackageName);
     }

     static WebViewFactoryProvider getProvider() {
         synchronized (sProviderLock) {
             // For now the main purpose of this function (and the factory abstraction) is to keep
             // us honest and minimize usage of WebView internals when binding the proxy.
             if (sProviderInstance != null) return sProviderInstance;

             loadNativeLibrary();

             Class<WebViewFactoryProvider> providerClass;
             try {
                 providerClass = getFactoryClass();
             } catch (ClassNotFoundException e) {
                 Log.e(LOGTAG, "error loading provider", e);
                 throw new AndroidRuntimeException(e);
             }

             StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
             try {
                 sProviderInstance = providerClass.newInstance();
                 if (DEBUG) Log.v(LOGTAG, "Loaded provider: " + sProviderInstance);
                 return sProviderInstance;
             } catch (Exception e) {
                 Log.e(LOGTAG, "error instantiating provider", e);
                 throw new AndroidRuntimeException(e);
             } finally {
                 StrictMode.setThreadPolicy(oldPolicy);
             }
         }
     }

     private static Class<WebViewFactoryProvider> getFactoryClass() throws ClassNotFoundException {
         Application initialApplication = AppGlobals.getInitialApplication();
         try {
             // First fetch the package info so we can log the webview package version.
             String packageName = getWebViewPackageName();
             PackageInfo pi = initialApplication.getPackageManager().getPackageInfo(packageName, 0);
             Log.i(LOGTAG, "Loading " + packageName + " version " + pi.versionName +
                           " (code " + pi.versionCode + ")");

             // Construct a package context to load the Java code into the current app.
             Context webViewContext = initialApplication.createPackageContext(packageName,
                     Context.CONTEXT_INCLUDE_CODE | Context.CONTEXT_IGNORE_SECURITY);
             initialApplication.getAssets().addAssetPath(
                     webViewContext.getApplicationInfo().sourceDir);
             ClassLoader clazzLoader = webViewContext.getClassLoader();
             return (Class<WebViewFactoryProvider>) Class.forName(CHROMIUM_WEBVIEW_FACTORY, true,
                                                                  clazzLoader);
         } catch (PackageManager.NameNotFoundException e) {
             // If the package doesn't exist, then try loading the null WebView instead.
             // If that succeeds, then this is a device without WebView support; if it fails then
             // swallow the failure, complain that the real WebView is missing and rethrow the
             // original exception.
             try {
                 return (Class<WebViewFactoryProvider>) Class.forName(NULL_WEBVIEW_FACTORY);
             } catch (ClassNotFoundException e2) {
                 // Ignore.
             }
             Log.e(LOGTAG, "Chromium WebView package does not exist", e);
             throw new AndroidRuntimeException(e);
         }
     }

     /**
      * Perform any WebView loading preparations that must happen in the zygote.
      * Currently, this means allocating address space to load the real JNI library later.
      */
     public static void prepareWebViewInZygote() {
         try {
             System.loadLibrary("webviewchromium_loader");
             long addressSpaceToReserve =
                     SystemProperties.getLong(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY,
                     CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES);
             sAddressSpaceReserved = nativeReserveAddressSpace(addressSpaceToReserve);

             if (sAddressSpaceReserved) {
                 if (DEBUG) {
                     Log.v(LOGTAG, "address space reserved: " + addressSpaceToReserve + " bytes");
                 }
             } else {
                 Log.e(LOGTAG, "reserving " + addressSpaceToReserve +
                         " bytes of address space failed");
             }
         } catch (Throwable t) {
             // Log and discard errors at this stage as we must not crash the zygote.
             Log.e(LOGTAG, "error preparing native loader", t);
         }
     }

     /**
      * Perform any WebView loading preparations that must happen at boot from the system server,
      * after the package manager has started or after an update to the webview is installed.
      * This must be called in the system server.
      * Currently, this means spawning the child processes which will create the relro files.
      */
     public static void prepareWebViewInSystemServer() {
         String[] nativePaths = null;
         try {
             nativePaths = getWebViewNativeLibraryPaths();
         } catch (PackageManager.NameNotFoundException e) {
         }
         prepareWebViewInSystemServer(nativePaths);
     }

     private static void prepareWebViewInSystemServer(String[] nativeLibraryPaths) {
         if (DEBUG) Log.v(LOGTAG, "creating relro files");

         // We must always trigger createRelRo regardless of the value of nativeLibraryPaths. Any
         // unexpected values will be handled there to ensure that we trigger notifying any process
         // waiting on relreo creation.
         if (Build.SUPPORTED_32_BIT_ABIS.length > 0) {
             if (DEBUG) Log.v(LOGTAG, "Create 32 bit relro");
             createRelroFile(false /* is64Bit */, nativeLibraryPaths);
         }

         if (Build.SUPPORTED_64_BIT_ABIS.length > 0) {
             if (DEBUG) Log.v(LOGTAG, "Create 64 bit relro");
             createRelroFile(true /* is64Bit */, nativeLibraryPaths);
         }
     }

     public static void onWebViewUpdateInstalled() {
         String[] nativeLibs = null;
         try {
             nativeLibs = WebViewFactory.getWebViewNativeLibraryPaths();
         } catch (PackageManager.NameNotFoundException e) {
         }

         if (nativeLibs != null) {
             long newVmSize = 0L;

             for (String path : nativeLibs) {
                 if (DEBUG) Log.d(LOGTAG, "Checking file size of " + path);
                 if (path == null) continue;
                 File f = new File(path);
                 if (f.exists()) {
                     long length = f.length();
                     if (length > newVmSize) {
                         newVmSize = length;
                     }
                 }
             }

             if (DEBUG) {
                 Log.v(LOGTAG, "Based on library size, need " + newVmSize +
                         " bytes of address space.");
             }
             // The required memory can be larger than the file on disk (due to .bss), and an
             // upgraded version of the library will likely be larger, so always attempt to reserve
             // twice as much as we think to allow for the library to grow during this boot cycle.
             newVmSize = Math.max(2 * newVmSize, CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES);
             Log.d(LOGTAG, "Setting new address space to " + newVmSize);
             SystemProperties.set(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY,
                     Long.toString(newVmSize));
         }
         prepareWebViewInSystemServer(nativeLibs);
     }

     private static String[] getWebViewNativeLibraryPaths()
             throws PackageManager.NameNotFoundException {
         final String NATIVE_LIB_FILE_NAME = "libwebviewchromium.so";

         PackageManager pm = AppGlobals.getInitialApplication().getPackageManager();
         ApplicationInfo ai = pm.getApplicationInfo(getWebViewPackageName(), 0);

         String path32;
         String path64;
         boolean primaryArchIs64bit = VMRuntime.is64BitAbi(ai.primaryCpuAbi);
         if (!TextUtils.isEmpty(ai.secondaryCpuAbi)) {
             // Multi-arch case.
             if (primaryArchIs64bit) {
                 // Primary arch: 64-bit, secondary: 32-bit.
                 path64 = ai.nativeLibraryDir;
                 path32 = ai.secondaryNativeLibraryDir;
             } else {
                 // Primary arch: 32-bit, secondary: 64-bit.
                 path64 = ai.secondaryNativeLibraryDir;
                 path32 = ai.nativeLibraryDir;
             }
         } else if (primaryArchIs64bit) {
             // Single-arch 64-bit.
             path64 = ai.nativeLibraryDir;
             path32 = "";
         } else {
             // Single-arch 32-bit.
             path32 = ai.nativeLibraryDir;
             path64 = "";
         }
         if (!TextUtils.isEmpty(path32)) path32 += "/" + NATIVE_LIB_FILE_NAME;
         if (!TextUtils.isEmpty(path64)) path64 += "/" + NATIVE_LIB_FILE_NAME;
         return new String[] { path32, path64 };
     }

     private static void createRelroFile(final boolean is64Bit, String[] nativeLibraryPaths) {
         final String abi =
                 is64Bit ? Build.SUPPORTED_64_BIT_ABIS[0] : Build.SUPPORTED_32_BIT_ABIS[0];

         // crashHandler is invoked by the ActivityManagerService when the isolated process crashes.
         Runnable crashHandler = new Runnable() {
             @Override
             public void run() {
                 try {
                     Log.e(LOGTAG, "relro file creator for " + abi + " crashed. Proceeding without");
                     getUpdateService().notifyRelroCreationCompleted(is64Bit, false);
                 } catch (RemoteException e) {
                     Log.e(LOGTAG, "Cannot reach WebViewUpdateService. " + e.getMessage());
                 }
             }
         };

         try {
             if (nativeLibraryPaths == null
                     || nativeLibraryPaths[0] == null || nativeLibraryPaths[1] == null) {
                 throw new IllegalArgumentException(
                         "Native library paths to the WebView RelRo process must not be null!");
             }
             int pid = LocalServices.getService(ActivityManagerInternal.class).startIsolatedProcess(
                     RelroFileCreator.class.getName(), nativeLibraryPaths, "WebViewLoader-" + abi, abi,
                     Process.SHARED_RELRO_UID, crashHandler);
             if (pid <= 0) throw new Exception("Failed to start the relro file creator process");
         } catch (Throwable t) {
             // Log and discard errors as we must not crash the system server.
             Log.e(LOGTAG, "error starting relro file creator for abi " + abi, t);
             crashHandler.run();
         }
     }

     private static class RelroFileCreator {
         // Called in an unprivileged child process to create the relro file.
         public static void main(String[] args) {
             boolean result = false;
             boolean is64Bit = VMRuntime.getRuntime().is64Bit();
             try{
                 if (args.length != 2 || args[0] == null || args[1] == null) {
                     Log.e(LOGTAG, "Invalid RelroFileCreator args: " + Arrays.toString(args));
                     return;
                 }
                 Log.v(LOGTAG, "RelroFileCreator (64bit = " + is64Bit + "), " +
                         " 32-bit lib: " + args[0] + ", 64-bit lib: " + args[1]);
                 if (!sAddressSpaceReserved) {
                     Log.e(LOGTAG, "can't create relro file; address space not reserved");
                     return;
                 }
                 result = nativeCreateRelroFile(args[0] /* path32 */,
                                                args[1] /* path64 */,
                                                CHROMIUM_WEBVIEW_NATIVE_RELRO_32,
                                                CHROMIUM_WEBVIEW_NATIVE_RELRO_64);
                 if (result && DEBUG) Log.v(LOGTAG, "created relro file");
             } finally {
                 // We must do our best to always notify the update service, even if something fails.
                 try {
                     getUpdateService().notifyRelroCreationCompleted(is64Bit, result);
                 } catch (RemoteException e) {
                     Log.e(LOGTAG, "error notifying update service", e);
                 }

                 if (!result) Log.e(LOGTAG, "failed to create relro file");

                 // Must explicitly exit or else this process will just sit around after we return.
                 System.exit(0);
             }
         }
     }

     private static void loadNativeLibrary() {
         if (!sAddressSpaceReserved) {
             Log.e(LOGTAG, "can't load with relro file; address space not reserved");
             return;
         }

         try {
             getUpdateService().waitForRelroCreationCompleted(VMRuntime.getRuntime().is64Bit());
         } catch (RemoteException e) {
             Log.e(LOGTAG, "error waiting for relro creation, proceeding without", e);
             return;
         }

         try {
             String[] args = getWebViewNativeLibraryPaths();
             boolean result = nativeLoadWithRelroFile(args[0] /* path32 */,
                                                      args[1] /* path64 */,
                                                      CHROMIUM_WEBVIEW_NATIVE_RELRO_32,
                                                      CHROMIUM_WEBVIEW_NATIVE_RELRO_64);
             if (!result) {
                 Log.w(LOGTAG, "failed to load with relro file, proceeding without");
             } else if (DEBUG) {
                 Log.v(LOGTAG, "loaded with relro file");
             }
         } catch (PackageManager.NameNotFoundException e) {
             Log.e(LOGTAG, "Failed to list WebView package libraries for loadNativeLibrary", e);
         }
     }

     private static IWebViewUpdateService getUpdateService() {
         return IWebViewUpdateService.Stub.asInterface(ServiceManager.getService("webviewupdate"));
     }

     private static native boolean nativeReserveAddressSpace(long addressSpaceToReserve);
     private static native boolean nativeCreateRelroFile(String lib32, String lib64,
                                                         String relro32, String relro64);
     private static native boolean nativeLoadWithRelroFile(String lib32, String lib64,
                                                           String relro32, String relro64);
 }
	/*
	* Copyright (C) 2012 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package android.webkit;

	import android.app.ActivityManagerInternal;
	import android.app.Application;
	import android.app.AppGlobals;
	import android.content.Context;
	import android.content.pm.ApplicationInfo;
	import android.content.pm.PackageInfo;
	import android.content.pm.PackageManager;
	import android.os.Build;
	import android.os.Process;
	import android.os.RemoteException;
	import android.os.ServiceManager;
	import android.os.StrictMode;
	import android.os.SystemProperties;
	import android.text.TextUtils;
	import android.util.AndroidRuntimeException;
	import android.util.Log;
	import com.android.server.LocalServices;
	import dalvik.system.VMRuntime;

	import java.io.File;
	import java.util.Arrays;

	import com.android.internal.os.Zygote;

	/**
	* Top level factory, used creating all the main WebView implementation classes.
	*
	* @hide
	*/
	public final class WebViewFactory {

	private static final String CHROMIUM_WEBVIEW_FACTORY =
	"com.android.webview.chromium.WebViewChromiumFactoryProvider";

	private static final String NULL_WEBVIEW_FACTORY =
	"com.android.webview.nullwebview.NullWebViewFactoryProvider";

	private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_32 =
	"/data/misc/shared_relro/libwebviewchromium32.relro";
	private static final String CHROMIUM_WEBVIEW_NATIVE_RELRO_64 =
	"/data/misc/shared_relro/libwebviewchromium64.relro";

	public static final String CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY =
	"persist.sys.webview.vmsize";
	private static final long CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES = 100 * 1024 * 1024;

	private static final String LOGTAG = "WebViewFactory";

	private static final boolean DEBUG = false;

	// Cache the factory both for efficiency, and ensure any one process gets all webviews from the
	// same provider.
	private static WebViewFactoryProvider sProviderInstance;
	private static final Object sProviderLock = new Object();
	private static boolean sAddressSpaceReserved = false;

	public static String getWebViewPackageName() {
	return AppGlobals.getInitialApplication().getString(
	com.android.internal.R.string.config_webViewPackageName);
	}

	static WebViewFactoryProvider getProvider() {
	synchronized (sProviderLock) {
	// For now the main purpose of this function (and the factory abstraction) is to keep
	// us honest and minimize usage of WebView internals when binding the proxy.
	if (sProviderInstance != null) return sProviderInstance;

	loadNativeLibrary();

	Class<WebViewFactoryProvider> providerClass;
	try {
	providerClass = getFactoryClass();
	} catch (ClassNotFoundException e) {
	Log.e(LOGTAG, "error loading provider", e);
	throw new AndroidRuntimeException(e);
	}

	StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
	try {
	sProviderInstance = providerClass.newInstance();
	if (DEBUG) Log.v(LOGTAG, "Loaded provider: " + sProviderInstance);
	return sProviderInstance;
	} catch (Exception e) {
	Log.e(LOGTAG, "error instantiating provider", e);
	throw new AndroidRuntimeException(e);
	} finally {
	StrictMode.setThreadPolicy(oldPolicy);
	}
	}
	}

	private static Class<WebViewFactoryProvider> getFactoryClass() throws ClassNotFoundException {
	Application initialApplication = AppGlobals.getInitialApplication();
	try {
	// First fetch the package info so we can log the webview package version.
	String packageName = getWebViewPackageName();
	PackageInfo pi = initialApplication.getPackageManager().getPackageInfo(packageName, 0);
	Log.i(LOGTAG, "Loading " + packageName + " version " + pi.versionName +
	" (code " + pi.versionCode + ")");

	// Construct a package context to load the Java code into the current app.
	Context webViewContext = initialApplication.createPackageContext(packageName,
	Context.CONTEXT_INCLUDE_CODE \| Context.CONTEXT_IGNORE_SECURITY);
	initialApplication.getAssets().addAssetPath(
	webViewContext.getApplicationInfo().sourceDir);
	ClassLoader clazzLoader = webViewContext.getClassLoader();
	return (Class<WebViewFactoryProvider>) Class.forName(CHROMIUM_WEBVIEW_FACTORY, true,
	clazzLoader);
	} catch (PackageManager.NameNotFoundException e) {
	// If the package doesn't exist, then try loading the null WebView instead.
	// If that succeeds, then this is a device without WebView support; if it fails then
	// swallow the failure, complain that the real WebView is missing and rethrow the
	// original exception.
	try {
	return (Class<WebViewFactoryProvider>) Class.forName(NULL_WEBVIEW_FACTORY);
	} catch (ClassNotFoundException e2) {
	// Ignore.
	}
	Log.e(LOGTAG, "Chromium WebView package does not exist", e);
	throw new AndroidRuntimeException(e);
	}
	}

	/**
	* Perform any WebView loading preparations that must happen in the zygote.
	* Currently, this means allocating address space to load the real JNI library later.
	*/
	public static void prepareWebViewInZygote() {
	try {
	System.loadLibrary("webviewchromium_loader");
	long addressSpaceToReserve =
	SystemProperties.getLong(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY,
	CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES);
	sAddressSpaceReserved = nativeReserveAddressSpace(addressSpaceToReserve);

	if (sAddressSpaceReserved) {
	if (DEBUG) {
	Log.v(LOGTAG, "address space reserved: " + addressSpaceToReserve + " bytes");
	}
	} else {
	Log.e(LOGTAG, "reserving " + addressSpaceToReserve +
	" bytes of address space failed");
	}
	} catch (Throwable t) {
	// Log and discard errors at this stage as we must not crash the zygote.
	Log.e(LOGTAG, "error preparing native loader", t);
	}
	}

	/**
	* Perform any WebView loading preparations that must happen at boot from the system server,
	* after the package manager has started or after an update to the webview is installed.
	* This must be called in the system server.
	* Currently, this means spawning the child processes which will create the relro files.
	*/
	public static void prepareWebViewInSystemServer() {
	String[] nativePaths = null;
	try {
	nativePaths = getWebViewNativeLibraryPaths();
	} catch (PackageManager.NameNotFoundException e) {
	}
	prepareWebViewInSystemServer(nativePaths);
	}

	private static void prepareWebViewInSystemServer(String[] nativeLibraryPaths) {
	if (DEBUG) Log.v(LOGTAG, "creating relro files");

	// We must always trigger createRelRo regardless of the value of nativeLibraryPaths. Any
	// unexpected values will be handled there to ensure that we trigger notifying any process
	// waiting on relreo creation.
	if (Build.SUPPORTED_32_BIT_ABIS.length > 0) {
	if (DEBUG) Log.v(LOGTAG, "Create 32 bit relro");
	createRelroFile(false /* is64Bit */, nativeLibraryPaths);
	}

	if (Build.SUPPORTED_64_BIT_ABIS.length > 0) {
	if (DEBUG) Log.v(LOGTAG, "Create 64 bit relro");
	createRelroFile(true /* is64Bit */, nativeLibraryPaths);
	}
	}

	public static void onWebViewUpdateInstalled() {
	String[] nativeLibs = null;
	try {
	nativeLibs = WebViewFactory.getWebViewNativeLibraryPaths();
	} catch (PackageManager.NameNotFoundException e) {
	}

	if (nativeLibs != null) {
	long newVmSize = 0L;

	for (String path : nativeLibs) {
	if (DEBUG) Log.d(LOGTAG, "Checking file size of " + path);
	if (path == null) continue;
	File f = new File(path);
	if (f.exists()) {
	long length = f.length();
	if (length > newVmSize) {
	newVmSize = length;
	}
	}
	}

	if (DEBUG) {
	Log.v(LOGTAG, "Based on library size, need " + newVmSize +
	" bytes of address space.");
	}
	// The required memory can be larger than the file on disk (due to .bss), and an
	// upgraded version of the library will likely be larger, so always attempt to reserve
	// twice as much as we think to allow for the library to grow during this boot cycle.
	newVmSize = Math.max(2 * newVmSize, CHROMIUM_WEBVIEW_DEFAULT_VMSIZE_BYTES);
	Log.d(LOGTAG, "Setting new address space to " + newVmSize);
	SystemProperties.set(CHROMIUM_WEBVIEW_VMSIZE_SIZE_PROPERTY,
	Long.toString(newVmSize));
	}
	prepareWebViewInSystemServer(nativeLibs);
	}

	private static String[] getWebViewNativeLibraryPaths()
	throws PackageManager.NameNotFoundException {
	final String NATIVE_LIB_FILE_NAME = "libwebviewchromium.so";

	PackageManager pm = AppGlobals.getInitialApplication().getPackageManager();
	ApplicationInfo ai = pm.getApplicationInfo(getWebViewPackageName(), 0);

	String path32;
	String path64;
	boolean primaryArchIs64bit = VMRuntime.is64BitAbi(ai.primaryCpuAbi);
	if (!TextUtils.isEmpty(ai.secondaryCpuAbi)) {
	// Multi-arch case.
	if (primaryArchIs64bit) {
	// Primary arch: 64-bit, secondary: 32-bit.
	path64 = ai.nativeLibraryDir;
	path32 = ai.secondaryNativeLibraryDir;
	} else {
	// Primary arch: 32-bit, secondary: 64-bit.
	path64 = ai.secondaryNativeLibraryDir;
	path32 = ai.nativeLibraryDir;
	}
	} else if (primaryArchIs64bit) {
	// Single-arch 64-bit.
	path64 = ai.nativeLibraryDir;
	path32 = "";
	} else {
	// Single-arch 32-bit.
	path32 = ai.nativeLibraryDir;
	path64 = "";
	}
	if (!TextUtils.isEmpty(path32)) path32 += "/" + NATIVE_LIB_FILE_NAME;
	if (!TextUtils.isEmpty(path64)) path64 += "/" + NATIVE_LIB_FILE_NAME;
	return new String[] { path32, path64 };
	}

	private static void createRelroFile(final boolean is64Bit, String[] nativeLibraryPaths) {
	final String abi =
	is64Bit ? Build.SUPPORTED_64_BIT_ABIS[0] : Build.SUPPORTED_32_BIT_ABIS[0];

	// crashHandler is invoked by the ActivityManagerService when the isolated process crashes.
	Runnable crashHandler = new Runnable() {
	@Override
	public void run() {
	try {
	Log.e(LOGTAG, "relro file creator for " + abi + " crashed. Proceeding without");
	getUpdateService().notifyRelroCreationCompleted(is64Bit, false);
	} catch (RemoteException e) {
	Log.e(LOGTAG, "Cannot reach WebViewUpdateService. " + e.getMessage());
	}
	}
	};

	try {
	if (nativeLibraryPaths == null
	\|\| nativeLibraryPaths[0] == null \|\| nativeLibraryPaths[1] == null) {
	throw new IllegalArgumentException(
	"Native library paths to the WebView RelRo process must not be null!");
	}
	int pid = LocalServices.getService(ActivityManagerInternal.class).startIsolatedProcess(
	RelroFileCreator.class.getName(), nativeLibraryPaths, "WebViewLoader-" + abi, abi,
	Process.SHARED_RELRO_UID, crashHandler);
	if (pid <= 0) throw new Exception("Failed to start the relro file creator process");
	} catch (Throwable t) {
	// Log and discard errors as we must not crash the system server.
	Log.e(LOGTAG, "error starting relro file creator for abi " + abi, t);
	crashHandler.run();
	}
	}

	private static class RelroFileCreator {
	// Called in an unprivileged child process to create the relro file.
	public static void main(String[] args) {
	boolean result = false;
	boolean is64Bit = VMRuntime.getRuntime().is64Bit();
	try{
	if (args.length != 2 \|\| args[0] == null \|\| args[1] == null) {
	Log.e(LOGTAG, "Invalid RelroFileCreator args: " + Arrays.toString(args));
	return;
	}
	Log.v(LOGTAG, "RelroFileCreator (64bit = " + is64Bit + "), " +
	" 32-bit lib: " + args[0] + ", 64-bit lib: " + args[1]);
	if (!sAddressSpaceReserved) {
	Log.e(LOGTAG, "can't create relro file; address space not reserved");
	return;
	}
	result = nativeCreateRelroFile(args[0] /* path32 */,
	args[1] /* path64 */,
	CHROMIUM_WEBVIEW_NATIVE_RELRO_32,
	CHROMIUM_WEBVIEW_NATIVE_RELRO_64);
	if (result && DEBUG) Log.v(LOGTAG, "created relro file");
	} finally {
	// We must do our best to always notify the update service, even if something fails.
	try {
	getUpdateService().notifyRelroCreationCompleted(is64Bit, result);
	} catch (RemoteException e) {
	Log.e(LOGTAG, "error notifying update service", e);
	}

	if (!result) Log.e(LOGTAG, "failed to create relro file");

	// Must explicitly exit or else this process will just sit around after we return.
	System.exit(0);
	}
	}
	}

	private static void loadNativeLibrary() {
	if (!sAddressSpaceReserved) {
	Log.e(LOGTAG, "can't load with relro file; address space not reserved");
	return;
	}

	try {
	getUpdateService().waitForRelroCreationCompleted(VMRuntime.getRuntime().is64Bit());
	} catch (RemoteException e) {
	Log.e(LOGTAG, "error waiting for relro creation, proceeding without", e);
	return;
	}

	try {
	String[] args = getWebViewNativeLibraryPaths();
	boolean result = nativeLoadWithRelroFile(args[0] /* path32 */,
	args[1] /* path64 */,
	CHROMIUM_WEBVIEW_NATIVE_RELRO_32,
	CHROMIUM_WEBVIEW_NATIVE_RELRO_64);
	if (!result) {
	Log.w(LOGTAG, "failed to load with relro file, proceeding without");
	} else if (DEBUG) {
	Log.v(LOGTAG, "loaded with relro file");
	}
	} catch (PackageManager.NameNotFoundException e) {
	Log.e(LOGTAG, "Failed to list WebView package libraries for loadNativeLibrary", e);
	}
	}

	private static IWebViewUpdateService getUpdateService() {
	return IWebViewUpdateService.Stub.asInterface(ServiceManager.getService("webviewupdate"));
	}

	private static native boolean nativeReserveAddressSpace(long addressSpaceToReserve);
	private static native boolean nativeCreateRelroFile(String lib32, String lib64,
	String relro32, String relro64);
	private static native boolean nativeLoadWithRelroFile(String lib32, String lib64,
	String relro32, String relro64);
	}