Merge "Purge proto tombstones when apps are uninstalled." (a139d7cb) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/os/NativeTombstoneManager.java

+88 −0

Original line number	Diff line number	Diff line
		@@ -22,11 +22,16 @@ import static android.os.Process.THREAD_PRIORITY_BACKGROUND;
		import android.annotation.AppIdInt;
		import android.annotation.Nullable;
		import android.annotation.UserIdInt;
		import android.content.BroadcastReceiver;
		import android.content.Context;
		import android.content.Intent;
		import android.content.IntentFilter;
		import android.os.FileObserver;
		import android.os.Handler;
		import android.os.ParcelFileDescriptor;
		import android.os.UserHandle;
		import android.system.ErrnoException;
		import android.system.Os;
		import android.util.Slog;
		import android.util.SparseArray;
		import android.util.proto.ProtoInputStream;
		@@ -75,6 +80,9 @@ public final class NativeTombstoneManager {
		}

		void onSystemReady() {
		registerForUserRemoval();
		registerForPackageRemoval();

		// Scan existing tombstones.
		mHandler.post(() -> {
		final File[] tombstoneFiles = TOMBSTONE_DIR.listFiles();
		@@ -145,6 +153,67 @@ public final class NativeTombstoneManager {
		}
		}

		private void purge(Optional<Integer> userId, Optional<Integer> appId) {
		mHandler.post(() -> {
		synchronized (mLock) {
		for (int i = mTombstones.size() - 1; i >= 0; --i) {
		TombstoneFile tombstone = mTombstones.valueAt(i);
		if (tombstone.matches(userId, appId)) {
		tombstone.purge();
		mTombstones.removeAt(i);
		}
		}
		}
		});
		}

		private void purgePackage(int uid, boolean allUsers) {
		final int appId = UserHandle.getAppId(uid);
		Optional<Integer> userId;
		if (allUsers) {
		userId = Optional.empty();
		} else {
		userId = Optional.of(UserHandle.getUserId(uid));
		}
		purge(userId, Optional.of(appId));
		}

		private void purgeUser(int uid) {
		purge(Optional.of(uid), Optional.empty());
		}

		private void registerForPackageRemoval() {
		final IntentFilter filter = new IntentFilter();
		filter.addAction(Intent.ACTION_PACKAGE_FULLY_REMOVED);
		filter.addDataScheme("package");
		mContext.registerReceiverForAllUsers(new BroadcastReceiver() {
		@Override
		public void onReceive(Context context, Intent intent) {
		final int uid = intent.getIntExtra(Intent.EXTRA_UID, UserHandle.USER_NULL);
		if (uid == UserHandle.USER_NULL) return;

		final boolean allUsers = intent.getBooleanExtra(
		Intent.EXTRA_REMOVED_FOR_ALL_USERS, false);

		purgePackage(uid, allUsers);
		}
		}, filter, null, mHandler);
		}

		private void registerForUserRemoval() {
		final IntentFilter filter = new IntentFilter();
		filter.addAction(Intent.ACTION_USER_REMOVED);
		mContext.registerReceiverForAllUsers(new BroadcastReceiver() {
		@Override
		public void onReceive(Context context, Intent intent) {
		final int userId = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, -1);
		if (userId < 1) return;

		purgeUser(userId);
		}
		}, filter, null, mHandler);
		}

		static class TombstoneFile {
		final ParcelFileDescriptor mPfd;

		@@ -179,6 +248,25 @@ public final class NativeTombstoneManager {
		IoUtils.closeQuietly(mPfd);
		}

		public void purge() {
		if (!mPurged) {
		// There's no way to atomically unlink a specific file for which we have an fd from
		// a path, which means that we can't safely delete a tombstone without coordination
		// with tombstoned (which has a risk of deadlock if for example, system_server hangs
		// with a flock). Do the next best thing, and just truncate the file.
		//
		// We don't have to worry about inflicting a SIGBUS on a process that has the
		// tombstone mmaped, because we only clear if the package has been removed, which
		// means no one with access to the tombstone should be left.
		try {
		Os.ftruncate(mPfd.getFileDescriptor(), 0);
		} catch (ErrnoException ex) {
		Slog.e(TAG, "Failed to truncate tombstone", ex);
		}
		mPurged = true;
		}
		}

		static Optional<TombstoneFile> parse(ParcelFileDescriptor pfd) {
		final FileInputStream is = new FileInputStream(pfd.getFileDescriptor());
		final ProtoInputStream stream = new ProtoInputStream(is);