Detect blocking binder calls in SystemUI (cc2d70f1) · Commits · e / os / android_frameworks_base

packages/SystemUI/src-debug/com/android/systemui/util/StartBinderLoggerModule.kt

0 → 100644

+31 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2023 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 com.android.systemui.util

		import com.android.systemui.CoreStartable
		import dagger.Binds
		import dagger.Module
		import dagger.multibindings.ClassKey
		import dagger.multibindings.IntoMap

		@Module
		abstract class StartBinderLoggerModule {
		@Binds
		@IntoMap
		@ClassKey(BinderLogger::class)
		abstract fun bindBinderLogger(impl: BinderLogger): CoreStartable
		}

packages/SystemUI/src-release/com/android/systemui/util/StartBinderLoggerModule.kt

0 → 100644

+24 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2023 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 com.android.systemui.util

		import dagger.Module

		@Module
		abstract class StartBinderLoggerModule {
		// Empty because this module is only used on debug builds
		}

packages/SystemUI/src/com/android/systemui/dagger/SystemUICoreStartableModule.kt

+2 −0

Original line number	Diff line number	Diff line
		@@ -55,6 +55,7 @@ import com.android.systemui.theme.ThemeOverlayController
		import com.android.systemui.toast.ToastUI
		import com.android.systemui.usb.StorageNotification
		import com.android.systemui.util.NotificationChannels
		import com.android.systemui.util.StartBinderLoggerModule
		import com.android.systemui.volume.VolumeUI
		import com.android.systemui.wmshell.WMShell
		import dagger.Binds
		@@ -68,6 +69,7 @@ import dagger.multibindings.IntoMap
		@Module(includes = [
		MultiUserUtilsModule::class,
		StartControlsStartableModule::class,
		StartBinderLoggerModule::class,
		])
		abstract class SystemUICoreStartableModule {
		/** Inject into AuthController. */

packages/SystemUI/src/com/android/systemui/util/BinderLogger.kt

0 → 100644

+282 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2023 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 com.android.systemui.util

		import android.os.Binder
		import android.os.Binder.ProxyTransactListener
		import android.os.Build
		import android.os.IBinder
		import android.os.StrictMode
		import android.os.StrictMode.ThreadPolicy
		import android.os.Trace.TRACE_TAG_APP
		import android.os.Trace.asyncTraceForTrackBegin
		import android.os.Trace.asyncTraceForTrackEnd
		import android.util.Log
		import com.android.settingslib.utils.ThreadUtils
		import com.android.systemui.CoreStartable
		import com.android.systemui.DejankUtils
		import com.android.systemui.dagger.SysUISingleton
		import com.android.systemui.flags.FeatureFlags
		import com.android.systemui.flags.Flags
		import javax.inject.Inject
		import kotlin.random.Random.Default.nextInt

		@SysUISingleton
		class BinderLogger
		@Inject
		constructor(
		private val featureFlags: FeatureFlags,
		) : CoreStartable, ProxyTransactListener {

		override fun start() {
		// This feature is only allowed on "userdebug" and "eng" builds
		if (Build.IS_USER) return
		if (!featureFlags.isEnabled(Flags.WARN_ON_BLOCKING_BINDER_TRANSACTIONS)) return
		if (DejankUtils.STRICT_MODE_ENABLED) {
		Log.e(
		TAG,
		"Feature disabled; persist.sysui.strictmode (DejankUtils) and " +
		"WARN_ON_BLOCKING_BINDER_TRANSACTIONS (BinderLogger) are incompatible"
		)
		return
		}
		Binder.setProxyTransactListener(this)
		val policyBuilder = ThreadPolicy.Builder().detectCustomSlowCalls().penaltyLog()
		StrictMode.setThreadPolicy(policyBuilder.build())
		}

		override fun onTransactStarted(binder: IBinder, transactionCode: Int, flags: Int): Any? {
		// Ignore one-way binder transactions
		if (flags and IBinder.FLAG_ONEWAY != 0) return null
		// Ignore anything not on the main thread
		if (!ThreadUtils.isMainThread()) return null

		// To make it easier to debug, log the most likely cause of the blocking binder transaction
		// by parsing the stack trace.
		val tr = Throwable()
		val analysis = BinderTransactionAnalysis.fromStackTrace(tr.stackTrace)
		val traceCookie = nextInt()
		asyncTraceForTrackBegin(TRACE_TAG_APP, TRACK_NAME, analysis.traceMessage, traceCookie)
		if (analysis.isSystemUi) {
		StrictMode.noteSlowCall(analysis.logMessage)
		} else {
		Log.v(TAG, analysis.logMessage, tr)
		}
		return traceCookie
		}

		override fun onTransactStarted(binder: IBinder, transactionCode: Int): Any? {
		return null
		}

		override fun onTransactEnded(o: Any?) {
		if (o is Int) {
		asyncTraceForTrackEnd(TRACE_TAG_APP, TRACK_NAME, o)
		}
		}

		/**
		* Class for finding the origin of a binder transaction from a stack trace and creating an error
		* message that indicates 1) whether or not the call originated from System UI, and 2) the name
		* of the binder transaction and where it was called.
		*
		* There are two types of stack traces:
		* 1. Stack traces that originate from System UI, which look like the following: ```
		* android.os.BinderProxy.transact(BinderProxy.java:541)
		* android.content.pm.BaseParceledListSlice.<init>(BaseParceledListSlice.java:94)
		* android.content.pm.ParceledListSlice.<init>(ParceledListSlice.java:42)
		* android.content.pm.ParceledListSlice.<init>(Unknown Source:0)
		* android.content.pm.ParceledListSlice$1.createFromParcel(ParceledListSlice.java:80)
		* android.content.pm.ParceledListSlice$1.createFromParcel(ParceledListSlice.java:78)
		* android.os.Parcel.readTypedObject(Parcel.java:3982)
		* android.content.pm.IPackageManager$Stub$Proxy.getInstalledPackages(IPackageManager.java:5029)
		* com.android.systemui.ExampleClass.runTwoWayBinderIPC(ExampleClass.kt:343) ... ``` Most of
		* these binder transactions contain a reference to a `$Stub$Proxy`, but some don't. For
		* example: ``` android.os.BinderProxy.transact(BinderProxy.java:541)
		* android.content.ContentProviderProxy.query(ContentProviderNative.java:479)
		* android.content.ContentResolver.query(ContentResolver.java:1219)
		* com.android.systemui.power.PowerUI.refreshEstimateIfNeeded(PowerUI.java:383) ``` In both
		* cases, we identify the call closest to a sysui package to make the error more clear.
		* 2. Stack traces that originate outside of System UI, which look like the following: ```
		* android.os.BinderProxy.transact(BinderProxy.java:541)
		* android.service.notification.IStatusBarNotificationHolder$Stub$Proxy.get(IStatusBarNotificationHolder.java:121)
		* android.service.notification.NotificationListenerService$NotificationListenerWrapper.onNotificationPosted(NotificationListenerService.java:1396)
		* android.service.notification.INotificationListener$Stub.onTransact(INotificationListener.java:248)
		* android.os.Binder.execTransactInternal(Binder.java:1285)
		* android.os.Binder.execTransact(Binder.java:1244) ```
		*
		* @param isSystemUi Whether or not the call originated from System UI. If it didn't, it's due
		* to internal implementation details of a core framework API.
		* @param cause The cause of the binder transaction
		* @param binderCall The binder transaction itself
		*/
		private class BinderTransactionAnalysis
		constructor(
		val isSystemUi: Boolean,
		cause: StackTraceElement?,
		binderCall: StackTraceElement?
		) {
		val logMessage: String
		val traceMessage: String

		init {
		val callName =
		(if (isSystemUi) getSimpleCallRefWithFileAndLineNumber(cause)
		else "${getSimpleCallRef(cause)}()") + " -> ${getBinderCallRef(binderCall)}"
		logMessage =
		"Blocking binder transaction detected" +
		(if (!isSystemUi) ", but the call did not originate from System UI" else "") +
		": $callName"
		traceMessage = "${if (isSystemUi) "sysui" else "core"}: $callName"
		}

		companion object {
		fun fromStackTrace(stackTrace: Array<StackTraceElement>): BinderTransactionAnalysis {
		if (stackTrace.size < 2) {
		return BinderTransactionAnalysis(false, null, null)
		}
		var previousStackElement: StackTraceElement = stackTrace.first()

		// The stack element corresponding to the binder transaction. For example:
		// `android.content.pm.IPackageManager$Stub$Proxy.getInstalledPackages(IPackageManager.java:50)`
		var binderTransaction: StackTraceElement? = null
		// The stack element that caused the binder transaction in the first place.
		// For example:
		// `com.android.systemui.ExampleClass.runTwoWayBinderIPC(ExampleClass.kt:343)`
		var causeOfBinderTransaction: StackTraceElement? = null

		// Iterate starting from the top of the stack (BinderProxy.transact).
		for (i in 1 until stackTrace.size) {
		val stackElement = stackTrace[i]
		if (previousStackElement.className?.endsWith("\$Stub\$Proxy") == true) {
		binderTransaction = previousStackElement
		causeOfBinderTransaction = stackElement
		}
		// As a heuristic, find the top-most call from a sysui package (besides this
		// class) and blame it
		val className = stackElement.className
		if (
		className != BinderLogger::class.java.name &&
		(className.startsWith(SYSUI_PKG) \|\| className.startsWith(KEYGUARD_PKG))
		) {
		causeOfBinderTransaction = stackElement

		return BinderTransactionAnalysis(
		true,
		causeOfBinderTransaction,
		// If an IInterface.Stub.Proxy-like call has not been identified yet,
		// blame the previous call in the stack.
		binderTransaction ?: previousStackElement
		)
		}
		previousStackElement = stackElement
		}
		// If we never found a call originating from sysui, report it with an explanation
		// that we could not find a culprit in sysui.
		return BinderTransactionAnalysis(false, causeOfBinderTransaction, binderTransaction)
		}
		}
		}

		companion object {
		private const val TAG: String = "SystemUIBinder"
		private const val TRACK_NAME = "Blocking Binder Transactions"
		private const val SYSUI_PKG = "com.android.systemui"
		private const val KEYGUARD_PKG = "com.android.keyguard"
		private const val UNKNOWN = "<unknown>"

		/**
		* Start of the source file for any R8 build within AOSP.
		*
		* TODO(b/213833843): Allow configuration of the prefix via a build variable.
		*/
		private const val AOSP_SOURCE_FILE_MARKER = "go/retraceme "

		/** Start of the source file for any R8 compiler build. */
		private const val R8_SOURCE_FILE_MARKER = "R8_"

		/**
		* Returns a short string for a [StackTraceElement] that references a binder transaction.
		* For example, a stack frame of
		* `android.content.pm.IPackageManager$Stub$Proxy.getInstalledPackages(IPackageManager.java:50)`
		* would return `android.content.pm.IPackageManager#getInstalledPackages()`
		*/
		private fun getBinderCallRef(stackFrame: StackTraceElement?): String =
		if (stackFrame != null) "${getBinderClassName(stackFrame)}#${stackFrame.methodName}()"
		else UNKNOWN

		/**
		* Returns the class name of a [StackTraceElement], removing any `$Stub$Proxy` suffix, but
		* still including the package name. This makes binder class names more readable. For
		* example, for a stack element of
		* `android.content.pm.IPackageManager$Stub$Proxy.getInstalledPackages(IPackageManager.java:50)`
		* this would return `android.content.pm.IPackageManager`
		*/
		private fun getBinderClassName(stackFrame: StackTraceElement): String {
		val className = stackFrame.className
		val stubDefIndex = className.indexOf("\$Stub\$Proxy")
		return if (stubDefIndex > 0) className.substring(0, stubDefIndex) else className
		}

		/**
		* Returns a short string for a [StackTraceElement], including the file name and line
		* number.
		*
		* If the source file needs retracing, this falls back to the default `toString()` method so
		* that it can be read by the `retrace` command-line tool (`m retrace`).
		*/
		private fun getSimpleCallRefWithFileAndLineNumber(stackFrame: StackTraceElement?): String =
		if (stackFrame != null) {
		with(stackFrame) {
		if (
		fileName == null \|\|
		fileName.startsWith(AOSP_SOURCE_FILE_MARKER) \|\|
		fileName.startsWith(R8_SOURCE_FILE_MARKER)
		) {
		// If the source file needs retracing, use the default toString() method for
		// compatibility with the retrace command-line tool
		"at $stackFrame"
		} else {
		"at ${getSimpleCallRef(stackFrame)}($fileName:$lineNumber)"
		}
		}
		} else UNKNOWN

		/**
		* Returns a short string for a [StackTraceElement] including it's class name and method
		* name. For example, if the stack frame is
		* `com.android.systemui.ExampleController.makeBlockingBinderIPC(ExampleController.kt:343)`
		* this would return `ExampleController#makeBlockingBinderIPC()`
		*/
		private fun getSimpleCallRef(stackFrame: StackTraceElement?): String =
		if (stackFrame != null) "${getSimpleClassName(stackFrame)}#${stackFrame.methodName}"
		else UNKNOWN

		/**
		* Returns a short string for a [StackTraceElement] including just its class name without
		* any package name. For example, if the stack frame is
		* `com.android.systemui.ExampleController.makeBlockingBinderIPC(ExampleController.kt:343)`
		* this would return `ExampleController`
		*/
		private fun getSimpleClassName(stackFrame: StackTraceElement): String =
		try {
		with(Class.forName(stackFrame.className)) {
		canonicalName?.substring(packageName.length + 1)
		}
		} finally {} ?: stackFrame.className
		}
		}