More flexible plugin protection layer (c1a17930) · Commits · e / os / android_frameworks_base

packages/SystemUI/plugin_core/processor/src/com/android/systemui/plugins/processor/ProtectedPluginProcessor.kt

+32 −11

Original line number	Diff line number	Diff line
		@@ -33,9 +33,10 @@ import kotlin.collections.ArrayDeque

		/**
		* [ProtectedPluginProcessor] generates a proxy implementation for interfaces annotated with
		* [ProtectedInterface] which catches [LinkageError]s generated by the proxied target. This protects
		* the plugin host from crashing due to out-of-date plugin code, where some call has changed so that
		* the [ClassLoader] can no longer resolve it correctly.
		* [ProtectedInterface] which catches [Exception]s generated by the proxied target. Production
		* plugin interfaces should use this to catch [LinkagError]s as that protects the plugin host from
		* crashing due to out-of-date plugin code, where some call has changed so that the [ClassLoader] is
		* no longer able to resolve it correctly.
		*
		* [PluginInstance] observes these failures via [ProtectedMethodListener] and unloads the plugin in
		* question to prevent further issues. This persists through further load/unload requests.
		@@ -61,6 +62,7 @@ class ProtectedPluginProcessor : AbstractProcessor() {
		val sourcePkg: String,
		val sourceName: String,
		val outputName: String,
		val exTypeAttr: ProtectedInterface,
		)

		override fun process(annotations: Set<TypeElement>, roundEnv: RoundEnvironment): Boolean {
		@@ -68,10 +70,19 @@ class ProtectedPluginProcessor : AbstractProcessor() {
		val additionalImports = mutableSetOf<String>()
		for (attr in annotations) {
		for (target in roundEnv.getElementsAnnotatedWith(attr)) {
		// Find the target exception types to be used
		var exTypeAttr = target.getAnnotation(ProtectedInterface::class.java)
		if (exTypeAttr == null \|\| exTypeAttr.exTypes.size == 0) {
		exTypeAttr = ProtectedInterface.Default
		}

		val sourceName = "${target.simpleName}"
		val outputName = "${sourceName}Protector"
		val pkg = (target.getEnclosingElement() as PackageElement).qualifiedName.toString()
		targets.put("$target", TargetData(attr, target, pkg, sourceName, outputName))
		targets.put(
		"$target",
		TargetData(attr, target, pkg, sourceName, outputName, exTypeAttr),
		)

		// This creates excessive imports, but it should be fine
		additionalImports.add("$pkg.$sourceName")
		@@ -80,7 +91,7 @@ class ProtectedPluginProcessor : AbstractProcessor() {
		}

		if (targets.size <= 0) return false
		for ((_, sourceType, sourcePkg, sourceName, outputName) in targets.values) {
		for ((_, sourceType, sourcePkg, sourceName, outputName, exTypeAttr) in targets.values) {
		// Find all methods in this type and all super types to that need to be implemented
		val types = ArrayDeque<TypeMirror>().apply { addLast(sourceType.asType()) }
		val impAttrs = mutableListOf<GeneratedImport>()
		@@ -105,7 +116,6 @@ class ProtectedPluginProcessor : AbstractProcessor() {

		// Imports used by the proxy implementation
		line("import android.util.Log;")
		line("import java.lang.LinkageError;")
		line("import com.android.systemui.plugins.PluginWrapper;")
		line("import com.android.systemui.plugins.ProtectedPluginListener;")
		line()
		@@ -118,6 +128,14 @@ class ProtectedPluginProcessor : AbstractProcessor() {
		line()
		}

		// Imports of caught exceptions
		if (exTypeAttr.exTypes.size > 0) {
		for (exType in exTypeAttr.exTypes) {
		line("import $exType;")
		}
		line()
		}

		// Imports declared via @GeneratedImport
		if (impAttrs.size > 0) {
		for (impAttr in impAttrs) {
		@@ -232,13 +250,16 @@ class ProtectedPluginProcessor : AbstractProcessor() {
		// Protect callsite in try/catch block
		braceBlock("try") { line(callStatement) }

		// Notify listener when a LinkageError is caught
		braceBlock("catch (LinkageError ex)") {
		// Notify listener when a target exception is caught
		for (exType in exTypeAttr.exTypes) {
		val simpleName = exType.substringAfterLast(".")
		braceBlock("catch ($simpleName ex)") {
		line("Log.wtf(CLASS, \"Failed to execute: \" + METHOD, ex);")
		line("mHasError = mListener.onFail(CLASS, METHOD, ex);")
		line(errorStatement)
		}
		}
		}
		line()
		}
		}

packages/SystemUI/plugin_core/src/com/android/systemui/plugins/ProtectedPluginListener.kt

+3 −4

Original line number	Diff line number	Diff line
		@@ -16,12 +16,11 @@ package com.android.systemui.plugins
		/** Listener for events from proxy types generated by [ProtectedPluginProcessor]. */
		interface ProtectedPluginListener {
		/**
		* Called when a method call produces a [LinkageError] before returning. This callback is
		* provided so that the host application can terminate the plugin or log the error as
		* appropriate.
		* Called when a method call produces a [Exception] before returning. This callback is provided
		* so that the host application can terminate the plugin or log the error as appropriate.
		*
		* @return true to terminate all methods within this object; false if the error is recoverable
		* and the proxied plugin should continue to operate as normal.
		*/
		fun onFail(className: String, methodName: String, failure: LinkageError): Boolean
		fun onFail(className: String, methodName: String, failure: Throwable): Boolean
		}

packages/SystemUI/plugin_core/src/com/android/systemui/plugins/annotations/ProtectedInterface.kt

+9 −5

Original line number	Diff line number	Diff line
		@@ -15,11 +15,15 @@ package com.android.systemui.plugins.annotations

		/**
		* This annotation marks denotes that an interface should use a proxy layer to protect the plugin
		* host from crashing due to [LinkageError]s originating within the plugin's implementation.
		* host from crashing due to the [Exception] types originating within the plugin's implementation.
		*/
		@Target(AnnotationTarget.CLASS)
		@Retention(AnnotationRetention.BINARY)
		annotation class ProtectedInterface
		annotation class ProtectedInterface(vararg val exTypes: String) {
		companion object {
		val Default = ProtectedInterface("java.lang.Exception", "java.lang.LinkageError")
		}
		}

		/**
		* This annotation specifies any additional imports that the processor will require when generating
		@@ -32,9 +36,9 @@ annotation class ProtectedInterface
		annotation class GeneratedImport(val extraImport: String)

		/**
		* This annotation provides default values to return when the proxy implementation catches a
		* [LinkageError]. The string specified should be a simple but valid java statement. In most cases
		* it should be a return statement of the appropriate type, but in some cases throwing a known
		* This annotation provides default values to return when the proxy implementation catches a target
		* [Exception]. The string specified should be a simple but valid java statement. In most cases it
		* should be a return statement of the appropriate type, but in some cases throwing a known
		* exception type may be preferred.
		*
		* This annotation is not required for methods that return void, but will behave the same way.

packages/SystemUI/shared/src/com/android/systemui/shared/plugins/PluginInstance.java

+4 −3

Original line number	Diff line number	Diff line
		@@ -108,7 +108,8 @@ public class PluginInstance<T extends Plugin>
		}

		@Override
		public synchronized boolean onFail(String className, String methodName, LinkageError failure) {
		public synchronized boolean onFail(String className, String methodName, Throwable failure) {
		Log.e(TAG, "Failure from " + mPlugin + ". Disabling Plugin.");
		mHasError = true;
		unloadPlugin();
		mListener.onPluginDetached(this);
		@@ -118,7 +119,7 @@ public class PluginInstance<T extends Plugin>
		/** Alerts listener and plugin that the plugin has been created. */
		public synchronized void onCreate() {
		if (mHasError) {
		log("Previous LinkageError detected for plugin class");
		log("Previous Fatal Exception detected for plugin class");
		return;
		}

		@@ -175,7 +176,7 @@ public class PluginInstance<T extends Plugin>
		*/
		public synchronized void loadPlugin() {
		if (mHasError) {
		log("Previous LinkageError detected for plugin class");
		log("Previous Fatal Exception detected for plugin class");
		return;
		}