Merge "Revert "Add crash detection and recovery."" into sc-dev (a2892ba0) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/graphics/fonts/FontCrashDetector.java

deleted100644 → 0

+0 −92

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		/*
		* Copyright (C) 2021 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.server.graphics.fonts;

		import android.annotation.NonNull;
		import android.util.Slog;

		import java.io.File;
		import java.io.IOException;

		/**
		* A class to detect font-related native crash.
		*
		* <p>If a fs-verity protected file is accessed through mmap and corrupted file block is detected,
		* SIGBUG signal is generated and the process will crash. To find corrupted files and remove them,
		* we use a marker file to detect crash.
		* <ol>
		* <li>Create a marker file before reading fs-verity protected font files.
		* <li>Delete the marker file after reading font files successfully.
		* <li>If the marker file is found in the next process startup, it means that the process
		* crashed before. We will delete font files to prevent crash loop.
		* </ol>
		*
		* <p>Example usage:
		* <pre>
		* FontCrashDetector detector = new FontCrashDetector(new File("/path/to/marker_file"));
		* if (detector.hasCrashed()) {
		* // Do cleanup
		* }
		* try (FontCrashDetector.MonitoredBlock b = detector.start()) {
		* // Read files
		* }
		* </pre>
		*
		* <p>This class DOES NOT detect Java exceptions. If a Java exception is thrown while monitoring
		* crash, the marker file will be deleted. Creating and deleting marker files are not lightweight.
		* Please use this class sparingly with caution.
		*/
		/* package */ final class FontCrashDetector {

		private static final String TAG = "FontCrashDetector";

		@NonNull
		private final File mMarkerFile;

		/* package */ FontCrashDetector(@NonNull File markerFile) {
		mMarkerFile = markerFile;
		}

		/* package */ boolean hasCrashed() {
		return mMarkerFile.exists();
		}

		/* package */ void clear() {
		if (!mMarkerFile.delete()) {
		Slog.e(TAG, "Could not delete marker file: " + mMarkerFile);
		}
		}

		/** Starts crash monitoring. */
		/* package */ MonitoredBlock start() {
		try {
		mMarkerFile.createNewFile();
		} catch (IOException e) {
		Slog.e(TAG, "Could not create marker file: " + mMarkerFile, e);
		}
		return new MonitoredBlock();
		}

		/** A helper class to monitor crash with try-with-resources syntax. */
		/* package */ class MonitoredBlock implements AutoCloseable {
		/** Ends crash monitoring. */
		@Override
		public void close() {
		clear();
		}
		}
		}

services/core/java/com/android/server/graphics/fonts/FontManagerService.java

+6 −27

Original line number	Diff line number	Diff line
		@@ -63,7 +63,6 @@ public final class FontManagerService extends IFontManager.Stub {
		private static final String TAG = "FontManagerService";

		private static final String FONT_FILES_DIR = "/data/fonts/files";
		private static final String CRASH_MARKER_FILE = "/data/fonts/config/crash.txt";

		@Override
		public FontConfig getFontConfig() {
		@@ -199,10 +198,6 @@ public final class FontManagerService extends IFontManager.Stub {

		private final Object mUpdatableFontDirLock = new Object();

		@GuardedBy("mUpdatableFontDirLock")
		@NonNull
		private final FontCrashDetector mFontCrashDetector;

		@GuardedBy("mUpdatableFontDirLock")
		@Nullable
		private final UpdatableFontDir mUpdatableFontDir;
		@@ -217,7 +212,6 @@ public final class FontManagerService extends IFontManager.Stub {

		private FontManagerService(Context context) {
		mContext = context;
		mFontCrashDetector = new FontCrashDetector(new File(CRASH_MARKER_FILE));
		mUpdatableFontDir = createUpdatableFontDir();
		initialize();
		}
		@@ -244,21 +238,10 @@ public final class FontManagerService extends IFontManager.Stub {
		}
		return;
		}
		if (mFontCrashDetector.hasCrashed()) {
		Slog.i(TAG, "Crash detected. Clearing font updates.");
		try {
		mUpdatableFontDir.clearUpdates();
		} catch (SystemFontException e) {
		Slog.e(TAG, "Failed to clear updates.", e);
		}
		mFontCrashDetector.clear();
		}
		try (FontCrashDetector.MonitoredBlock ignored = mFontCrashDetector.start()) {
		mUpdatableFontDir.loadFontFileMap();
		updateSerializedFontMap();
		}
		}
		}

		@NonNull
		public Context getContext() {
		@@ -286,12 +269,10 @@ public final class FontManagerService extends IFontManager.Stub {
		FontManager.RESULT_ERROR_VERSION_MISMATCH,
		"The base config version is older than current.");
		}
		try (FontCrashDetector.MonitoredBlock ignored = mFontCrashDetector.start()) {
		mUpdatableFontDir.update(requests);
		updateSerializedFontMap();
		}
		}
		}

		/* package */ void clearUpdates() throws SystemFontException {
		if (mUpdatableFontDir == null) {
		@@ -300,12 +281,10 @@ public final class FontManagerService extends IFontManager.Stub {
		"The font updater is disabled.");
		}
		synchronized (mUpdatableFontDirLock) {
		try (FontCrashDetector.MonitoredBlock ignored = mFontCrashDetector.start()) {
		mUpdatableFontDir.clearUpdates();
		updateSerializedFontMap();
		}
		}
		}

		/* package */ Map<String, File> getFontFileMap() {
		if (mUpdatableFontDir == null) {

services/tests/servicestests/src/com/android/server/graphics/fonts/FontCrashDetectorTest.java

deleted100644 → 0

+0 −77

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		/*
		* Copyright (C) 2021 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.server.graphics.fonts;

		import static com.google.common.truth.Truth.assertThat;

		import android.content.Context;
		import android.os.FileUtils;
		import android.platform.test.annotations.Presubmit;

		import androidx.test.InstrumentationRegistry;
		import androidx.test.filters.SmallTest;
		import androidx.test.runner.AndroidJUnit4;

		import org.junit.Before;
		import org.junit.Test;
		import org.junit.runner.RunWith;

		import java.io.File;

		@Presubmit
		@SmallTest
		@RunWith(AndroidJUnit4.class)
		public final class FontCrashDetectorTest {

		private File mCacheDir;

		@SuppressWarnings("ResultOfMethodCallIgnored")
		@Before
		public void setUp() {
		Context context = InstrumentationRegistry.getInstrumentation().getTargetContext();
		mCacheDir = new File(context.getCacheDir(), "UpdatableFontDirTest");
		FileUtils.deleteContentsAndDir(mCacheDir);
		mCacheDir.mkdirs();
		}

		@Test
		public void detectCrash() throws Exception {
		// Prepare a marker file.
		File file = new File(mCacheDir, "detectCrash");
		assertThat(file.createNewFile()).isTrue();

		FontCrashDetector detector = new FontCrashDetector(file);
		assertThat(detector.hasCrashed()).isTrue();

		detector.clear();
		assertThat(detector.hasCrashed()).isFalse();
		assertThat(file.exists()).isFalse();
		}

		@Test
		public void monitorCrash() {
		File file = new File(mCacheDir, "monitorCrash");
		FontCrashDetector detector = new FontCrashDetector(file);
		assertThat(detector.hasCrashed()).isFalse();

		FontCrashDetector.MonitoredBlock block = detector.start();
		assertThat(file.exists()).isTrue();

		block.close();
		assertThat(file.exists()).isFalse();
		}
		}

tests/UpdatableSystemFontTest/Android.bp

+0 −4

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		@@ -26,13 +26,9 @@ java_test_host {
		srcs: ["src/*/.java"],
		libs: ["tradefed", "compatibility-tradefed", "compatibility-host-util"],
		static_libs: [
		"block_device_writer_jar",
		"frameworks-base-hostutils",
		],
		test_suites: ["general-tests", "vts"],
		target_required: [
		"block_device_writer_module",
		],
		data: [
		":NotoColorEmojiTtf",
		":UpdatableSystemFontTestCertDer",

tests/UpdatableSystemFontTest/AndroidTest.xml

+0 −1

Original line number	Diff line number	Diff line
		@@ -21,7 +21,6 @@

		<target_preparer class="com.android.tradefed.targetprep.PushFilePreparer">
		<option name="cleanup" value="true" />
		<option name="push" value="block_device_writer->/data/local/tmp/block_device_writer" />
		<option name="push" value="UpdatableSystemFontTestCert.der->/data/local/tmp/UpdatableSystemFontTestCert.der" />
		<option name="push" value="NotoColorEmoji.ttf->/data/local/tmp/NotoColorEmoji.ttf" />
		<option name="push" value="UpdatableSystemFontTestNotoColorEmoji.ttf.fsv_sig->/data/local/tmp/UpdatableSystemFontTestNotoColorEmoji.ttf.fsv_sig" />