diff --git a/core/java/android/hardware/fingerprint/FingerprintManager.java b/core/java/android/hardware/fingerprint/FingerprintManager.java
index b00e65a..324a08c 100644
--- a/core/java/android/hardware/fingerprint/FingerprintManager.java
+++ b/core/java/android/hardware/fingerprint/FingerprintManager.java
@@ -932,7 +932,6 @@
             } else if (mAuthenticationCallback != null) {
                 mAuthenticationCallback.onAuthenticationError(clientErrMsgId,
                         getErrorString(errMsgId, vendorCode));
-                mAuthenticationCallback = null;
             } else if (mRemovalCallback != null) {
                 mRemovalCallback.onRemovalError(mRemovalFingerprint, clientErrMsgId,
                         getErrorString(errMsgId, vendorCode));
@@ -953,7 +952,6 @@
                 final AuthenticationResult result =
                         new AuthenticationResult(mCryptoObject, fp, userId);
                 mAuthenticationCallback.onAuthenticationSucceeded(result);
-                mAuthenticationCallback = null;
             }
         }
 
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
index 3a39e91..3542500 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
@@ -813,10 +813,10 @@
 
     public void onDensityOrFontScaleChanged() {
         initDimens();
-        if (mIsSummaryWithChildren) {
-            if (mChildrenContainer != null) {
-                mChildrenContainer.reInflateViews(mExpandClickListener, mEntry.notification);
-            }
+        // Let's update our childrencontainer. This is intentionally not guarded with
+        // mIsSummaryWithChildren since we might have had children but not anymore.
+        if (mChildrenContainer != null) {
+            mChildrenContainer.reInflateViews(mExpandClickListener, mEntry.notification);
         }
         if (mGuts != null) {
             View oldGuts = mGuts;
@@ -1458,9 +1458,11 @@
     public void setUserLocked(boolean userLocked) {
         mUserLocked = userLocked;
         mPrivateLayout.setUserExpanding(userLocked);
-        if (mIsSummaryWithChildren) {
+        // This is intentionally not guarded with mIsSummaryWithChildren since we might have had
+        // children but not anymore.
+        if (mChildrenContainer != null) {
             mChildrenContainer.setUserLocked(userLocked);
-            if (userLocked || !isGroupExpanded()) {
+            if (mIsSummaryWithChildren && (userLocked || !isGroupExpanded())) {
                 updateBackgroundForGroupState();
             }
         }
@@ -2189,4 +2191,9 @@
             }
         }
     }
+
+    @VisibleForTesting
+    protected void setChildrenContainer(NotificationChildrenContainer childrenContainer) {
+        mChildrenContainer = childrenContainer;
+    }
 }
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationChildrenContainer.java b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationChildrenContainer.java
index 3f211e3..0dbd1d6 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationChildrenContainer.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationChildrenContainer.java
@@ -29,6 +29,7 @@
 import android.widget.RemoteViews;
 import android.widget.TextView;
 
+import com.android.internal.annotations.VisibleForTesting;
 import com.android.systemui.R;
 import com.android.systemui.statusbar.CrossFadeHelper;
 import com.android.systemui.statusbar.ExpandableNotificationRow;
@@ -1223,4 +1224,9 @@
         }
         return getGroupExpandFraction();
     }
+
+    @VisibleForTesting
+    public boolean isUserLocked() {
+        return mUserLocked;
+    }
 }
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/ExpandableNotificationRowTest.java b/packages/SystemUI/tests/src/com/android/systemui/statusbar/ExpandableNotificationRowTest.java
index bc79116..a3a0a6f 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/ExpandableNotificationRowTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/ExpandableNotificationRowTest.java
@@ -16,7 +16,9 @@
 
 package com.android.systemui.statusbar;
 
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
 
 import android.content.Context;
 import android.support.test.InstrumentationRegistry;
@@ -26,6 +28,8 @@
 import android.support.test.runner.AndroidJUnit4;
 import android.view.View;
 
+import com.android.systemui.statusbar.stack.NotificationChildrenContainer;
+
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Ignore;
@@ -65,4 +69,25 @@
                 == View.VISIBLE);
     }
 
+    @Test
+    public void testUserLockedResetEvenWhenNoChildren() {
+        mGroup.setUserLocked(true);
+        mGroup.removeAllChildren();
+        mGroup.setUserLocked(false);
+        Assert.assertFalse("The childrencontainer should not be userlocked but is, the state "
+                + "seems out of sync.", mGroup.getChildrenContainer().isUserLocked());
+    }
+
+    @Test
+    public void testReinflatedOnDensityChange() {
+        mGroup.setUserLocked(true);
+        mGroup.removeAllChildren();
+        mGroup.setUserLocked(false);
+        NotificationChildrenContainer mockContainer = mock(NotificationChildrenContainer.class);
+        mGroup.setChildrenContainer(mockContainer);
+        mGroup.onDensityOrFontScaleChanged();
+        verify(mockContainer).reInflateViews(any(), any());
+    }
+
+
 }
diff --git a/services/autofill/java/com/android/server/autofill/Session.java b/services/autofill/java/com/android/server/autofill/Session.java
index f3ca075..bad8dcf 100644
--- a/services/autofill/java/com/android/server/autofill/Session.java
+++ b/services/autofill/java/com/android/server/autofill/Session.java
@@ -682,7 +682,6 @@
                 removeSelf();
                 return;
             }
-            resetViewStatesLocked(dataset, ViewState.STATE_WAITING_DATASET_AUTH);
         }
 
         final Parcelable result = data.getParcelable(AutofillManager.EXTRA_AUTHENTICATION_RESULT);
@@ -1362,7 +1361,6 @@
             }
 
             // ...or handle authentication.
-            // TODO(b/37424539): proper implementation
             mService.setDatasetAuthenticationSelected(dataset.getId());
             setViewStatesLocked(null, dataset, ViewState.STATE_WAITING_DATASET_AUTH, false);
             final Intent fillInIntent = createAuthFillInIntent(
@@ -1455,21 +1453,36 @@
             }
             try {
                 if (sDebug) Slog.d(TAG, "autoFillApp(): the buck is on the app: " + dataset);
+
                 // Skip null values as a null values means no change
                 final int entryCount = dataset.getFieldIds().size();
                 final List<AutofillId> ids = new ArrayList<>(entryCount);
                 final List<AutofillValue> values = new ArrayList<>(entryCount);
+                boolean waitingDatasetAuth = false;
                 for (int i = 0; i < entryCount; i++) {
                     if (dataset.getFieldValues().get(i) == null) {
                         continue;
                     }
-                    ids.add(dataset.getFieldIds().get(i));
+                    final AutofillId viewId = dataset.getFieldIds().get(i);
+                    ids.add(viewId);
                     values.add(dataset.getFieldValues().get(i));
+                    final ViewState viewState = mViewStates.get(viewId);
+                    if (viewState != null
+                            && (viewState.getState() & ViewState.STATE_WAITING_DATASET_AUTH) != 0) {
+                        if (sVerbose) {
+                            Slog.v(TAG, "autofillApp(): view " + viewId + " waiting auth");
+                        }
+                        waitingDatasetAuth = true;
+                        viewState.resetState(ViewState.STATE_WAITING_DATASET_AUTH);
+                    }
                 }
                 if (!ids.isEmpty()) {
+                    if (waitingDatasetAuth) {
+                        hideFillUiIfOwnedByMe();
+                    }
                     mClient.autofill(id, ids, values);
+                    setViewStatesLocked(null, dataset, ViewState.STATE_AUTOFILLED, false);
                 }
-                setViewStatesLocked(null, dataset, ViewState.STATE_AUTOFILLED, false);
             } catch (RemoteException e) {
                 Slog.w(TAG, "Error autofilling activity: " + e);
             }
diff --git a/services/autofill/java/com/android/server/autofill/ViewState.java b/services/autofill/java/com/android/server/autofill/ViewState.java
index f87fa19..8a52c96 100644
--- a/services/autofill/java/com/android/server/autofill/ViewState.java
+++ b/services/autofill/java/com/android/server/autofill/ViewState.java
@@ -174,7 +174,7 @@
      * fill UI is ready to be displayed (i.e. when response and bounds are set).
      */
     void maybeCallOnFillReady() {
-        if ((mState & (STATE_AUTOFILLED | STATE_WAITING_DATASET_AUTH)) != 0) {
+        if ((mState & STATE_AUTOFILLED) != 0) {
             if (sDebug) Slog.d(TAG, "Ignoring UI for " + id + " on " + getStateAsString());
             return;
         }
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 7ae4138..4b12bc4 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -175,6 +175,9 @@
         implements PendingIntent.OnFinished {
     private static final String TAG = ConnectivityService.class.getSimpleName();
 
+    public static final String DIAG_ARG = "--diag";
+    public static final String SHORT_ARG = "--short";
+
     private static final boolean DBG = true;
     private static final boolean VDBG = false;
 
@@ -1852,7 +1855,7 @@
         final IndentingPrintWriter pw = new IndentingPrintWriter(writer, "  ");
         if (!DumpUtils.checkDumpPermission(mContext, TAG, pw)) return;
 
-        if (argsContain(args, "--diag")) {
+        if (argsContain(args, DIAG_ARG)) {
             dumpNetworkDiagnostics(pw);
             return;
         }
@@ -1938,7 +1941,7 @@
             pw.decreaseIndent();
         }
 
-        if (argsContain(args, "--short") == false) {
+        if (argsContain(args, SHORT_ARG) == false) {
             pw.println();
             synchronized (mValidationLogs) {
                 pw.println("mValidationLogs (most recent first):");
diff --git a/services/core/java/com/android/server/connectivity/Tethering.java b/services/core/java/com/android/server/connectivity/Tethering.java
index 81a1458..901092e 100644
--- a/services/core/java/com/android/server/connectivity/Tethering.java
+++ b/services/core/java/com/android/server/connectivity/Tethering.java
@@ -20,6 +20,7 @@
 import static android.hardware.usb.UsbManager.USB_FUNCTION_RNDIS;
 import static android.net.wifi.WifiManager.EXTRA_WIFI_AP_STATE;
 import static android.net.wifi.WifiManager.WIFI_AP_STATE_DISABLED;
+import static com.android.server.ConnectivityService.SHORT_ARG;
 
 import android.app.Notification;
 import android.app.NotificationManager;
@@ -47,6 +48,7 @@
 import android.net.NetworkState;
 import android.net.NetworkUtils;
 import android.net.RouteInfo;
+import android.net.util.SharedLog;
 import android.net.wifi.WifiManager;
 import android.os.Binder;
 import android.os.Bundle;
@@ -62,7 +64,6 @@
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 import android.util.ArrayMap;
-import android.util.LocalLog;
 import android.util.Log;
 import android.util.SparseArray;
 
@@ -147,9 +148,7 @@
         }
     }
 
-    private final static int MAX_LOG_RECORDS = 500;
-
-    private final LocalLog mLocalLog = new LocalLog(MAX_LOG_RECORDS);
+    private final SharedLog mLog = new SharedLog(TAG);
 
     // used to synchronize public access to members
     private final Object mPublicSync;
@@ -180,7 +179,7 @@
     public Tethering(Context context, INetworkManagementService nmService,
             INetworkStatsService statsService, INetworkPolicyManager policyManager,
             Looper looper, MockableSystemProperties systemProperties) {
-        mLocalLog.log("CONSTRUCTED");
+        mLog.mark("constructed");
         mContext = context;
         mNMService = nmService;
         mStatsService = statsService;
@@ -195,9 +194,9 @@
         mTetherMasterSM = new TetherMasterSM("TetherMaster", mLooper);
         mTetherMasterSM.start();
 
-        mOffloadController = new OffloadController(mTetherMasterSM.getHandler());
+        mOffloadController = new OffloadController(mTetherMasterSM.getHandler(), mLog);
         mUpstreamNetworkMonitor = new UpstreamNetworkMonitor(
-                mContext, mTetherMasterSM, TetherMasterSM.EVENT_UPSTREAM_CALLBACK);
+                mContext, mTetherMasterSM, TetherMasterSM.EVENT_UPSTREAM_CALLBACK, mLog);
         mForwardedDownstreams = new HashSet<>();
 
         mStateReceiver = new StateReceiver();
@@ -1094,7 +1093,7 @@
             addState(mSetDnsForwardersErrorState);
 
             mNotifyList = new ArrayList<>();
-            mIPv6TetheringCoordinator = new IPv6TetheringCoordinator(mNotifyList);
+            mIPv6TetheringCoordinator = new IPv6TetheringCoordinator(mNotifyList, mLog);
             setInitialState(mInitialState);
         }
 
@@ -1141,7 +1140,7 @@
                 try {
                     mNMService.setIpForwardingEnabled(true);
                 } catch (Exception e) {
-                    mLocalLog.log("ERROR " + e);
+                    mLog.e(e);
                     transitionTo(mSetIpForwardingEnabledErrorState);
                     return false;
                 }
@@ -1154,12 +1153,12 @@
                         mNMService.stopTethering();
                         mNMService.startTethering(cfg.dhcpRanges);
                     } catch (Exception ee) {
-                        mLocalLog.log("ERROR " + ee);
+                        mLog.e(ee);
                         transitionTo(mStartTetheringErrorState);
                         return false;
                     }
                 }
-                mLocalLog.log("SET master tether settings: ON");
+                mLog.log("SET master tether settings: ON");
                 return true;
             }
 
@@ -1167,19 +1166,19 @@
                 try {
                     mNMService.stopTethering();
                 } catch (Exception e) {
-                    mLocalLog.log("ERROR " + e);
+                    mLog.e(e);
                     transitionTo(mStopTetheringErrorState);
                     return false;
                 }
                 try {
                     mNMService.setIpForwardingEnabled(false);
                 } catch (Exception e) {
-                    mLocalLog.log("ERROR " + e);
+                    mLog.e(e);
                     transitionTo(mSetIpForwardingDisabledErrorState);
                     return false;
                 }
                 transitionTo(mInitialState);
-                mLocalLog.log("SET master tether settings: OFF");
+                mLog.log("SET master tether settings: OFF");
                 return true;
             }
 
@@ -1305,13 +1304,13 @@
                 }
                 try {
                     mNMService.setDnsForwarders(network, dnsServers);
-                    mLocalLog.log(String.format(
-                            "SET DNS forwarders: network=%s dnsServers=[%s]",
+                    mLog.log(String.format(
+                            "SET DNS forwarders: network=%s dnsServers=%s",
                             network, Arrays.toString(dnsServers)));
                 } catch (Exception e) {
                     // TODO: Investigate how this can fail and what exactly
                     // happens if/when such failures occur.
-                    mLocalLog.log("ERROR setting DNS forwarders failed, " + e);
+                    mLog.e("setting DNS forwarders failed, " + e);
                     transitionTo(mSetDnsForwardersErrorState);
                 }
             }
@@ -1788,12 +1787,23 @@
 
         pw.println("Log:");
         pw.increaseIndent();
-        mLocalLog.readOnlyLocalLog().dump(fd, pw, args);
+        if (argsContain(args, SHORT_ARG)) {
+            pw.println("<log removed for brevity>");
+        } else {
+            mLog.dump(fd, pw, args);
+        }
         pw.decreaseIndent();
 
         pw.decreaseIndent();
     }
 
+    private static boolean argsContain(String[] args, String target) {
+        for (String arg : args) {
+            if (arg.equals(target)) return true;
+        }
+        return false;
+    }
+
     @Override
     public void notifyInterfaceStateChange(String iface, TetherInterfaceStateMachine who,
                                            int state, int error) {
@@ -1807,8 +1817,7 @@
             }
         }
 
-        mLocalLog.log(String.format("OBSERVED iface=%s state=%s error=%s",
-                iface, state, error));
+        mLog.log(String.format("OBSERVED iface=%s state=%s error=%s", iface, state, error));
 
         try {
             // Notify that we're tethering (or not) this interface.
@@ -1846,8 +1855,8 @@
     private void trackNewTetherableInterface(String iface, int interfaceType) {
         TetherState tetherState;
         tetherState = new TetherState(new TetherInterfaceStateMachine(iface, mLooper,
-                interfaceType, mNMService, mStatsService, this,
-                new IPv6TetheringInterfaceServices(iface, mNMService)));
+                interfaceType, mLog, mNMService, mStatsService, this,
+                new IPv6TetheringInterfaceServices(iface, mNMService, mLog)));
         mTetherStates.put(iface, tetherState);
         tetherState.stateMachine.start();
     }
diff --git a/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringCoordinator.java b/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringCoordinator.java
index 2485654..518f6c1 100644
--- a/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringCoordinator.java
+++ b/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringCoordinator.java
@@ -25,6 +25,7 @@
 import android.net.NetworkState;
 import android.net.RouteInfo;
 import android.net.util.NetworkConstants;
+import android.net.util.SharedLog;
 import android.util.Log;
 
 import java.net.Inet6Address;
@@ -64,6 +65,7 @@
     }
 
     private final ArrayList<TetherInterfaceStateMachine> mNotifyList;
+    private final SharedLog mLog;
     // NOTE: mActiveDownstreams is a list and not a hash data structure because
     // we keep active downstreams in arrival order.  This is done so /64s can
     // be parceled out on a "first come, first served" basis and a /64 used by
@@ -74,8 +76,10 @@
     private short mNextSubnetId;
     private NetworkState mUpstreamNetworkState;
 
-    public IPv6TetheringCoordinator(ArrayList<TetherInterfaceStateMachine> notifyList) {
+    public IPv6TetheringCoordinator(ArrayList<TetherInterfaceStateMachine> notifyList,
+                                    SharedLog log) {
         mNotifyList = notifyList;
+        mLog = log.forSubComponent(TAG);
         mActiveDownstreams = new LinkedList<>();
         mUniqueLocalPrefix = generateUniqueLocalPrefix();
         mNextSubnetId = 0;
@@ -115,7 +119,7 @@
         if (VDBG) {
             Log.d(TAG, "updateUpstreamNetworkState: " + toDebugString(ns));
         }
-        if (!canTetherIPv6(ns)) {
+        if (!canTetherIPv6(ns, mLog)) {
             stopIPv6TetheringOnAllInterfaces();
             setUpstreamNetworkState(null);
             return;
@@ -150,9 +154,7 @@
                     null);
         }
 
-        if (DBG) {
-            Log.d(TAG, "setUpstreamNetworkState: " + toDebugString(mUpstreamNetworkState));
-        }
+        mLog.log("setUpstreamNetworkState: " + toDebugString(mUpstreamNetworkState));
     }
 
     private void updateIPv6TetheringInterfaces() {
@@ -206,7 +208,7 @@
         return null;
     }
 
-    private static boolean canTetherIPv6(NetworkState ns) {
+    private static boolean canTetherIPv6(NetworkState ns, SharedLog sharedLog) {
         // Broadly speaking:
         //
         //     [1] does the upstream have an IPv6 default route?
@@ -260,13 +262,11 @@
 
         final boolean outcome = canTether && supportedConfiguration;
 
-        if (VDBG) {
-            if (ns == null) {
-                Log.d(TAG, "No available upstream.");
-            } else {
-                Log.d(TAG, String.format("IPv6 tethering is %s for upstream: %s",
-                        (outcome ? "available" : "not available"), toDebugString(ns)));
-            }
+        if (ns == null) {
+            sharedLog.log("No available upstream.");
+        } else {
+            sharedLog.log(String.format("IPv6 tethering is %s for upstream: %s",
+                    (outcome ? "available" : "not available"), toDebugString(ns)));
         }
 
         return outcome;
diff --git a/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringInterfaceServices.java b/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringInterfaceServices.java
index c6a7925..adf4af8 100644
--- a/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringInterfaceServices.java
+++ b/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringInterfaceServices.java
@@ -28,10 +28,10 @@
 import android.net.ip.RouterAdvertisementDaemon;
 import android.net.ip.RouterAdvertisementDaemon.RaParams;
 import android.net.util.NetdService;
+import android.net.util.SharedLog;
 import android.os.INetworkManagementService;
 import android.os.ServiceSpecificException;
 import android.os.RemoteException;
-import android.util.Log;
 import android.util.Slog;
 
 import java.net.Inet6Address;
@@ -54,6 +54,7 @@
 
     private final String mIfName;
     private final INetworkManagementService mNMService;
+    private final SharedLog mLog;
 
     private NetworkInterface mNetworkInterface;
     private byte[] mHwAddr;
@@ -61,9 +62,11 @@
     private RouterAdvertisementDaemon mRaDaemon;
     private RaParams mLastRaParams;
 
-    public IPv6TetheringInterfaceServices(String ifname, INetworkManagementService nms) {
+    public IPv6TetheringInterfaceServices(
+            String ifname, INetworkManagementService nms, SharedLog log) {
         mIfName = ifname;
         mNMService = nms;
+        mLog = log.forSubComponent(mIfName);
     }
 
     public boolean start() {
@@ -72,12 +75,12 @@
         try {
             mNetworkInterface = NetworkInterface.getByName(mIfName);
         } catch (SocketException e) {
-            Log.e(TAG, "Error looking up NetworkInterfaces for " + mIfName, e);
+            mLog.e("Error looking up NetworkInterfaces: " + e);
             stop();
             return false;
         }
         if (mNetworkInterface == null) {
-            Log.e(TAG, "Failed to find NetworkInterface for " + mIfName);
+            mLog.e("Failed to find NetworkInterface");
             stop();
             return false;
         }
@@ -85,7 +88,7 @@
         try {
             mHwAddr = mNetworkInterface.getHardwareAddress();
         } catch (SocketException e) {
-            Log.e(TAG, "Failed to find hardware address for " + mIfName, e);
+            mLog.e("Failed to find hardware address: " + e);
             stop();
             return false;
         }
@@ -161,11 +164,11 @@
             try {
                 final int removalFailures = mNMService.removeRoutesFromLocalNetwork(toBeRemoved);
                 if (removalFailures > 0) {
-                    Log.e(TAG, String.format("Failed to remove %d IPv6 routes from local table.",
+                    mLog.e(String.format("Failed to remove %d IPv6 routes from local table.",
                             removalFailures));
                 }
             } catch (RemoteException e) {
-                Log.e(TAG, "Failed to remove IPv6 routes from local table: ", e);
+                mLog.e("Failed to remove IPv6 routes from local table: " + e);
             }
         }
 
@@ -195,7 +198,7 @@
                     // error (EEXIST is silently ignored).
                     mNMService.addInterfaceToLocalNetwork(mIfName, toBeAdded);
                 } catch (RemoteException e) {
-                    Log.e(TAG, "Failed to add IPv6 routes to local table: ", e);
+                    mLog.e("Failed to add IPv6 routes to local table: " + e);
                 }
             }
         }
@@ -206,7 +209,7 @@
         final INetd netd = NetdService.getInstance();
         if (netd == null) {
             if (newDnses != null) newDnses.clear();
-            Log.e(TAG, "No netd service instance available; not setting local IPv6 addresses");
+            mLog.e("No netd service instance available; not setting local IPv6 addresses");
             return;
         }
 
@@ -217,7 +220,7 @@
                 try {
                     netd.interfaceDelAddress(mIfName, dnsString, RFC7421_PREFIX_LENGTH);
                 } catch (ServiceSpecificException | RemoteException e) {
-                    Log.e(TAG, "Failed to remove local dns IP: " + dnsString, e);
+                    mLog.e("Failed to remove local dns IP " + dnsString + ": " + e);
                 }
             }
         }
@@ -234,7 +237,7 @@
                 try {
                     netd.interfaceAddAddress(mIfName, dnsString, RFC7421_PREFIX_LENGTH);
                 } catch (ServiceSpecificException | RemoteException e) {
-                    Log.e(TAG, "Failed to add local dns IP: " + dnsString, e);
+                    mLog.e("Failed to add local dns IP " + dnsString + ": " + e);
                     newDnses.remove(dns);
                 }
             }
@@ -243,7 +246,7 @@
         try {
             netd.tetherApplyDnsInterfaces();
         } catch (ServiceSpecificException | RemoteException e) {
-            Log.e(TAG, "Failed to update local DNS caching server");
+            mLog.e("Failed to update local DNS caching server");
             if (newDnses != null) newDnses.clear();
         }
     }
diff --git a/services/core/java/com/android/server/connectivity/tethering/OffloadController.java b/services/core/java/com/android/server/connectivity/tethering/OffloadController.java
index 220e751..8f21d99 100644
--- a/services/core/java/com/android/server/connectivity/tethering/OffloadController.java
+++ b/services/core/java/com/android/server/connectivity/tethering/OffloadController.java
@@ -18,7 +18,7 @@
 
 import android.net.LinkProperties;
 import android.os.Handler;
-import android.util.Log;
+import android.net.util.SharedLog;
 
 /**
  * A wrapper around hardware offload interface.
@@ -29,16 +29,18 @@
     private static final String TAG = OffloadController.class.getSimpleName();
 
     private final Handler mHandler;
+    private final SharedLog mLog;
     private LinkProperties mUpstreamLinkProperties;
 
-    public OffloadController(Handler h) {
+    public OffloadController(Handler h, SharedLog log) {
         mHandler = h;
+        mLog = log.forSubComponent(TAG);
     }
 
     public void start() {
         // TODO: initOffload() and configure callbacks to be handled on our
         // preferred Handler.
-        Log.d(TAG, "tethering offload not supported");
+        mLog.i("tethering offload not supported");
     }
 
     public void stop() {
diff --git a/services/core/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachine.java b/services/core/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachine.java
index d3cfd87..4a1d405 100644
--- a/services/core/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachine.java
+++ b/services/core/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachine.java
@@ -22,6 +22,7 @@
 import android.net.LinkAddress;
 import android.net.LinkProperties;
 import android.net.NetworkUtils;
+import android.net.util.SharedLog;
 import android.os.INetworkManagementService;
 import android.os.Looper;
 import android.os.Message;
@@ -82,6 +83,7 @@
     private final State mTetheredState;
     private final State mUnavailableState;
 
+    private final SharedLog mLog;
     private final INetworkManagementService mNMService;
     private final INetworkStatsService mStatsService;
     private final IControlsTethering mTetherController;
@@ -93,10 +95,12 @@
     private int mLastError;
     private String mMyUpstreamIfaceName;  // may change over time
 
-    public TetherInterfaceStateMachine(String ifaceName, Looper looper, int interfaceType,
-                    INetworkManagementService nMService, INetworkStatsService statsService,
-                    IControlsTethering tetherController, IPv6TetheringInterfaceServices ipv6Svc) {
+    public TetherInterfaceStateMachine(
+            String ifaceName, Looper looper, int interfaceType, SharedLog log,
+            INetworkManagementService nMService, INetworkStatsService statsService,
+            IControlsTethering tetherController, IPv6TetheringInterfaceServices ipv6Svc) {
         super(ifaceName, looper);
+        mLog = log.forSubComponent(ifaceName);
         mNMService = nMService;
         mStatsService = statsService;
         mTetherController = tetherController;
@@ -162,7 +166,7 @@
                 mNMService.setInterfaceConfig(mIfaceName, ifcg);
             }
         } catch (Exception e) {
-            Log.e(TAG, "Error configuring interface " + mIfaceName, e);
+            mLog.e("Error configuring interface " + e);
             return false;
         }
 
@@ -203,7 +207,7 @@
                             transitionTo(mTetheredState);
                             break;
                         default:
-                            Log.e(TAG, "Invalid tethering interface serving state specified.");
+                            mLog.e("Invalid tethering interface serving state specified.");
                     }
                     break;
                 case CMD_INTERFACE_DOWN:
@@ -232,13 +236,13 @@
             try {
                 mNMService.tetherInterface(mIfaceName);
             } catch (Exception e) {
-                Log.e(TAG, "Error Tethering: " + e.toString());
+                mLog.e("Error Tethering: " + e);
                 mLastError = ConnectivityManager.TETHER_ERROR_TETHER_IFACE_ERROR;
                 return;
             }
 
             if (!mIPv6TetherSvc.start()) {
-                Log.e(TAG, "Failed to start IPv6TetheringInterfaceServices");
+                mLog.e("Failed to start IPv6TetheringInterfaceServices");
                 // TODO: Make this a fatal error once Bluetooth IPv6 is sorted.
                 return;
             }
@@ -255,7 +259,7 @@
                 mNMService.untetherInterface(mIfaceName);
             } catch (Exception e) {
                 mLastError = ConnectivityManager.TETHER_ERROR_UNTETHER_IFACE_ERROR;
-                Log.e(TAG, "Failed to untether interface: " + e.toString());
+                mLog.e("Failed to untether interface: " + e);
             }
 
             configureIfaceIp(false);
@@ -316,7 +320,7 @@
             maybeLogMessage(this, message.what);
             switch (message.what) {
                 case CMD_TETHER_REQUESTED:
-                    Log.e(TAG, "CMD_TETHER_REQUESTED while in local hotspot mode.");
+                    mLog.e("CMD_TETHER_REQUESTED while in local-only hotspot mode.");
                     break;
                 case CMD_TETHER_CONNECTION_CHANGED:
                     // Ignored in local hotspot state.
@@ -389,7 +393,7 @@
             boolean retValue = true;
             switch (message.what) {
                 case CMD_TETHER_REQUESTED:
-                    Log.e(TAG, "CMD_TETHER_REQUESTED while already tethering.");
+                    mLog.e("CMD_TETHER_REQUESTED while already tethering.");
                     break;
                 case CMD_TETHER_CONNECTION_CHANGED:
                     String newUpstreamIfaceName = (String)(message.obj);
@@ -406,7 +410,7 @@
                             mNMService.startInterfaceForwarding(mIfaceName,
                                     newUpstreamIfaceName);
                         } catch (Exception e) {
-                            Log.e(TAG, "Exception enabling Nat: " + e.toString());
+                            mLog.e("Exception enabling NAT: " + e);
                             cleanupUpstreamInterface(newUpstreamIfaceName);
                             mLastError = ConnectivityManager.TETHER_ERROR_ENABLE_NAT_ERROR;
                             transitionTo(mInitialState);
diff --git a/services/core/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitor.java b/services/core/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitor.java
index 97a2d5e..be71490 100644
--- a/services/core/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitor.java
+++ b/services/core/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitor.java
@@ -29,6 +29,7 @@
 import android.net.NetworkCapabilities;
 import android.net.NetworkRequest;
 import android.net.NetworkState;
+import android.net.util.SharedLog;
 import android.util.Log;
 
 import com.android.internal.annotations.VisibleForTesting;
@@ -73,6 +74,7 @@
     private static final int CALLBACK_MOBILE_REQUEST = 3;
 
     private final Context mContext;
+    private final SharedLog mLog;
     private final StateMachine mTarget;
     private final Handler mHandler;
     private final int mWhat;
@@ -84,16 +86,18 @@
     private boolean mDunRequired;
     private Network mCurrentDefault;
 
-    public UpstreamNetworkMonitor(Context ctx, StateMachine tgt, int what) {
+    public UpstreamNetworkMonitor(Context ctx, StateMachine tgt, int what, SharedLog log) {
         mContext = ctx;
         mTarget = tgt;
         mHandler = mTarget.getHandler();
         mWhat = what;
+        mLog = log.forSubComponent(TAG);
     }
 
     @VisibleForTesting
-    public UpstreamNetworkMonitor(StateMachine tgt, int what, ConnectivityManager cm) {
-        this(null, tgt, what);
+    public UpstreamNetworkMonitor(
+            StateMachine tgt, int what, ConnectivityManager cm, SharedLog log) {
+        this(null, tgt, what, log);
         mCM = cm;
     }
 
@@ -136,7 +140,7 @@
 
     public void registerMobileNetworkRequest() {
         if (mMobileNetworkCallback != null) {
-            Log.e(TAG, "registerMobileNetworkRequest() already registered");
+            mLog.e("registerMobileNetworkRequest() already registered");
             return;
         }
 
@@ -156,7 +160,7 @@
         // TODO: Change the timeout from 0 (no onUnavailable callback) to some
         // moderate callback timeout. This might be useful for updating some UI.
         // Additionally, we log a message to aid in any subsequent debugging.
-        Log.d(TAG, "requesting mobile upstream network: " + mobileUpstreamRequest);
+        mLog.i("requesting mobile upstream network: " + mobileUpstreamRequest);
 
         cm().requestNetwork(mobileUpstreamRequest, mMobileNetworkCallback, 0, legacyType, mHandler);
     }
diff --git a/services/net/java/android/net/util/SharedLog.java b/services/net/java/android/net/util/SharedLog.java
new file mode 100644
index 0000000..343d237
--- /dev/null
+++ b/services/net/java/android/net/util/SharedLog.java
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2017 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.net.util;
+
+import android.text.TextUtils;
+import android.util.LocalLog;
+import android.util.Log;
+
+import java.io.FileDescriptor;
+import java.io.PrintWriter;
+import java.util.StringJoiner;
+
+
+/**
+ * Class to centralize logging functionality for tethering.
+ *
+ * All access to class methods other than dump() must be on the same thread.
+ *
+ * @hide
+ */
+public class SharedLog {
+    private final static int DEFAULT_MAX_RECORDS = 500;
+    private final static String COMPONENT_DELIMITER = ".";
+
+    private enum Category {
+        NONE,
+        ERROR,
+        MARK,
+        WARN,
+    };
+
+    private final LocalLog mLocalLog;
+    // The tag to use for output to the system log. This is not output to the
+    // LocalLog because that would be redundant.
+    private final String mTag;
+    // The component (or subcomponent) of a system that is sharing this log.
+    // This can grow in depth if components call forSubComponent() to obtain
+    // their SharedLog instance. The tag is not included in the component for
+    // brevity.
+    private final String mComponent;
+
+    public SharedLog(String tag) {
+        this(DEFAULT_MAX_RECORDS, tag);
+    }
+
+    public SharedLog(int maxRecords, String tag) {
+        this(new LocalLog(maxRecords), tag, tag);
+    }
+
+    private SharedLog(LocalLog localLog, String tag, String component) {
+        mLocalLog = localLog;
+        mTag = tag;
+        mComponent = component;
+    }
+
+    public SharedLog forSubComponent(String component) {
+        if (!isRootLogInstance()) {
+            component = mComponent + COMPONENT_DELIMITER + component;
+        }
+        return new SharedLog(mLocalLog, mTag, component);
+    }
+
+    public void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
+        mLocalLog.readOnlyLocalLog().dump(fd, writer, args);
+    }
+
+    //////
+    // Methods that both log an entry and emit it to the system log.
+    //////
+
+    public void e(Exception e) {
+        Log.e(mTag, record(Category.ERROR, e.toString()));
+    }
+
+    public void e(String msg) {
+        Log.e(mTag, record(Category.ERROR, msg));
+    }
+
+    public void i(String msg) {
+        Log.i(mTag, record(Category.NONE, msg));
+    }
+
+    public void w(String msg) {
+        Log.w(mTag, record(Category.WARN, msg));
+    }
+
+    //////
+    // Methods that only log an entry (and do NOT emit to the system log).
+    //////
+
+    public void log(String msg) {
+        record(Category.NONE, msg);
+    }
+
+    public void mark(String msg) {
+        record(Category.MARK, msg);
+    }
+
+    private String record(Category category, String msg) {
+        final String entry = logLine(category, msg);
+        mLocalLog.log(entry);
+        return entry;
+    }
+
+    private String logLine(Category category, String msg) {
+        final StringJoiner sj = new StringJoiner(" ");
+        if (!isRootLogInstance()) sj.add("[" + mComponent + "]");
+        if (category != Category.NONE) sj.add(category.toString());
+        return sj.add(msg).toString();
+    }
+
+    // Check whether this SharedLog instance is nominally the top level in
+    // a potential hierarchy of shared logs (the root of a tree),
+    // or is a subcomponent within the hierarchy.
+    private boolean isRootLogInstance() {
+        return TextUtils.isEmpty(mComponent) || mComponent.equals(mTag);
+    }
+}
diff --git a/tests/net/java/android/net/util/SharedLogTest.java b/tests/net/java/android/net/util/SharedLogTest.java
new file mode 100644
index 0000000..7fd7a63
--- /dev/null
+++ b/tests/net/java/android/net/util/SharedLogTest.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2017 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.net.util;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintWriter;
+import java.util.ArrayList;
+import java.util.Vector;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class SharedLogTest {
+    private static final String TIMESTAMP_PATTERN =
+            "^[0-9][0-9]-[0-9][0-9] [0-9][0-9]:[0-9][0-9]:[0-9][0-9].[0-9][0-9][0-9]";
+    private static final String TIMESTAMP = "mm-dd HH:MM:SS.xxx";
+
+    @Test
+    public void testBasicOperation() {
+        final SharedLog logTop = new SharedLog("top");
+        logTop.mark("first post!");
+
+        final SharedLog logLevel2a = logTop.forSubComponent("twoA");
+        final SharedLog logLevel2b = logTop.forSubComponent("twoB");
+        logLevel2b.e("2b or not 2b");
+        logLevel2a.w("second post?");
+
+        final SharedLog logLevel3 = logLevel2a.forSubComponent("three");
+        logTop.log("still logging");
+        logLevel3.log("3 >> 2");
+        logLevel2a.mark("ok: last post");
+
+        final String[] expected = {
+            TIMESTAMP + " - MARK first post!",
+            TIMESTAMP + " - [twoB] ERROR 2b or not 2b",
+            TIMESTAMP + " - [twoA] WARN second post?",
+            TIMESTAMP + " - still logging",
+            TIMESTAMP + " - [twoA.three] 3 >> 2",
+            TIMESTAMP + " - [twoA] MARK ok: last post",
+        };
+        // Verify the logs are all there and in the correct order.
+        verifyLogLines(expected, logTop);
+
+        // In fact, because they all share the same underlying LocalLog,
+        // every subcomponent SharedLog's dump() is identical.
+        verifyLogLines(expected, logLevel2a);
+        verifyLogLines(expected, logLevel2b);
+        verifyLogLines(expected, logLevel3);
+    }
+
+    private static void verifyLogLines(String[] expected, SharedLog log) {
+        final ByteArrayOutputStream ostream = new ByteArrayOutputStream();
+        final PrintWriter pw = new PrintWriter(ostream, true);
+        log.dump(null, pw, null);
+
+        final String dumpOutput = ostream.toString();
+        assertTrue(dumpOutput != null);
+        assertTrue(!"".equals(dumpOutput));
+
+        final String[] lines = dumpOutput.split("\n");
+        assertEquals(expected.length, lines.length);
+
+        for (int i = 0; i < lines.length; i++) {
+            // Fix up the timestamps.
+            lines[i] = lines[i].replaceAll(TIMESTAMP_PATTERN, TIMESTAMP);
+        }
+
+        for (int i = 0; i < expected.length; i++) {
+            assertEquals(expected[i], lines[i]);
+        }
+    }
+}
diff --git a/tests/net/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachineTest.java b/tests/net/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachineTest.java
index a3f33dc..27e683c 100644
--- a/tests/net/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachineTest.java
+++ b/tests/net/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachineTest.java
@@ -38,6 +38,7 @@
 import android.net.ConnectivityManager;
 import android.net.INetworkStatsService;
 import android.net.InterfaceConfiguration;
+import android.net.util.SharedLog;
 import android.os.INetworkManagementService;
 import android.os.RemoteException;
 import android.os.test.TestLooper;
@@ -63,12 +64,14 @@
     @Mock private IControlsTethering mTetherHelper;
     @Mock private InterfaceConfiguration mInterfaceConfiguration;
     @Mock private IPv6TetheringInterfaceServices mIPv6TetheringInterfaceServices;
+    @Mock private SharedLog mSharedLog;
 
     private final TestLooper mLooper = new TestLooper();
     private TetherInterfaceStateMachine mTestedSm;
 
     private void initStateMachine(int interfaceType) throws Exception {
-        mTestedSm = new TetherInterfaceStateMachine(IFACE_NAME, mLooper.getLooper(), interfaceType,
+        mTestedSm = new TetherInterfaceStateMachine(
+                IFACE_NAME, mLooper.getLooper(), interfaceType, mSharedLog,
                 mNMService, mStatsService, mTetherHelper, mIPv6TetheringInterfaceServices);
         mTestedSm.start();
         // Starting the state machine always puts us in a consistent state and notifies
@@ -90,12 +93,13 @@
 
     @Before public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
+        when(mSharedLog.forSubComponent(anyString())).thenReturn(mSharedLog);
     }
 
     @Test
     public void startsOutAvailable() {
         mTestedSm = new TetherInterfaceStateMachine(IFACE_NAME, mLooper.getLooper(),
-                TETHERING_BLUETOOTH, mNMService, mStatsService, mTetherHelper,
+                TETHERING_BLUETOOTH, mSharedLog, mNMService, mStatsService, mTetherHelper,
                 mIPv6TetheringInterfaceServices);
         mTestedSm.start();
         mLooper.dispatchAll();
diff --git a/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java b/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java
index c72efb0..9bb392a 100644
--- a/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java
+++ b/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java
@@ -25,11 +25,13 @@
 import static org.junit.Assert.fail;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.anyInt;
+import static org.mockito.Mockito.anyString;
 import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.when;
 
 import android.content.Context;
 import android.os.Handler;
@@ -40,6 +42,7 @@
 import android.net.Network;
 import android.net.NetworkCapabilities;
 import android.net.NetworkRequest;
+import android.net.util.SharedLog;
 
 import android.support.test.filters.SmallTest;
 import android.support.test.runner.AndroidJUnit4;
@@ -69,6 +72,7 @@
 
     @Mock private Context mContext;
     @Mock private IConnectivityManager mCS;
+    @Mock private SharedLog mLog;
 
     private TestStateMachine mSM;
     private TestConnectivityManager mCM;
@@ -78,10 +82,12 @@
         MockitoAnnotations.initMocks(this);
         reset(mContext);
         reset(mCS);
+        reset(mLog);
+        when(mLog.forSubComponent(anyString())).thenReturn(mLog);
 
         mCM = spy(new TestConnectivityManager(mContext, mCS));
         mSM = new TestStateMachine();
-        mUNM = new UpstreamNetworkMonitor(mSM, EVENT_UNM_UPDATE, (ConnectivityManager) mCM);
+        mUNM = new UpstreamNetworkMonitor(mSM, EVENT_UNM_UPDATE, (ConnectivityManager) mCM, mLog);
     }
 
     @After public void tearDown() throws Exception {