diff --git a/core/java/android/inputmethodservice/InputMethodService.java b/core/java/android/inputmethodservice/InputMethodService.java
index c3e3180b6717c..fbc0732affe1c 100644
--- a/core/java/android/inputmethodservice/InputMethodService.java
+++ b/core/java/android/inputmethodservice/InputMethodService.java
@@ -83,6 +83,7 @@ import android.os.Bundle;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
+import android.os.Process;
 import android.os.ResultReceiver;
 import android.os.SystemClock;
 import android.os.SystemProperties;
@@ -926,7 +927,7 @@ public class InputMethodService extends AbstractInputMethodService {
                 mOnPreparedStylusHwCalled = true;
             }
             if (onStartStylusHandwriting()) {
-                mPrivOps.onStylusHandwritingReady(requestId);
+                mPrivOps.onStylusHandwritingReady(requestId, Process.myPid());
             } else {
                 Log.i(TAG, "IME is not ready. Can't start Stylus Handwriting");
                 // TODO(b/210039666): see if it's valuable to propagate this back to IMM.
diff --git a/core/java/com/android/internal/inputmethod/IInputMethodPrivilegedOperations.aidl b/core/java/com/android/internal/inputmethod/IInputMethodPrivilegedOperations.aidl
index 30853bc2ecc54..b18c98b58516d 100644
--- a/core/java/com/android/internal/inputmethod/IInputMethodPrivilegedOperations.aidl
+++ b/core/java/com/android/internal/inputmethod/IInputMethodPrivilegedOperations.aidl
@@ -42,6 +42,6 @@ oneway interface IInputMethodPrivilegedOperations {
     void shouldOfferSwitchingToNextInputMethod(in AndroidFuture future /* T=Boolean */);
     void notifyUserActionAsync();
     void applyImeVisibilityAsync(IBinder showOrHideInputToken, boolean setVisible);
-    void onStylusHandwritingReady(int requestId);
+    void onStylusHandwritingReady(int requestId, int pid);
     void finishStylusHandwriting(int requestId);
 }
diff --git a/core/java/com/android/internal/inputmethod/InputMethodPrivilegedOperations.java b/core/java/com/android/internal/inputmethod/InputMethodPrivilegedOperations.java
index 2a7e1dcedd436..e8a2d810d563d 100644
--- a/core/java/com/android/internal/inputmethod/InputMethodPrivilegedOperations.java
+++ b/core/java/com/android/internal/inputmethod/InputMethodPrivilegedOperations.java
@@ -396,16 +396,16 @@ public final class InputMethodPrivilegedOperations {
     }
 
     /**
-     * Calls {@link IInputMethodPrivilegedOperations#onStylusHandwritingReady()}
+     * Calls {@link IInputMethodPrivilegedOperations#onStylusHandwritingReady(int, int)}
      */
     @AnyThread
-    public void onStylusHandwritingReady(int requestId) {
+    public void onStylusHandwritingReady(int requestId, int pid) {
         final IInputMethodPrivilegedOperations ops = mOps.getAndWarnIfNull();
         if (ops == null) {
             return;
         }
         try {
-            ops.onStylusHandwritingReady(requestId);
+            ops.onStylusHandwritingReady(requestId, pid);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
diff --git a/services/core/java/com/android/server/inputmethod/HandwritingEventReceiverSurface.java b/services/core/java/com/android/server/inputmethod/HandwritingEventReceiverSurface.java
index 9846a2ba48a4e..3c454080ef1c2 100644
--- a/services/core/java/com/android/server/inputmethod/HandwritingEventReceiverSurface.java
+++ b/services/core/java/com/android/server/inputmethod/HandwritingEventReceiverSurface.java
@@ -82,13 +82,14 @@ final class HandwritingEventReceiverSurface {
         mIsIntercepting = false;
     }
 
-    void startIntercepting() {
-        // TODO(b/210978621): Update the spy window's PID and UID to be associated with the IME so
-        //  that ANRs are correctly attributed to the IME.
-        final SurfaceControl.Transaction t = new SurfaceControl.Transaction();
+    void startIntercepting(int imePid, int imeUid) {
+        mWindowHandle.ownerPid = imePid;
+        mWindowHandle.ownerUid = imeUid;
         mWindowHandle.inputFeatures &= ~WindowManager.LayoutParams.INPUT_FEATURE_SPY;
-        t.setInputWindowInfo(mInputSurface, mWindowHandle);
-        t.apply();
+
+        new SurfaceControl.Transaction()
+                .setInputWindowInfo(mInputSurface, mWindowHandle)
+                .apply();
         mIsIntercepting = true;
     }
 
diff --git a/services/core/java/com/android/server/inputmethod/HandwritingModeController.java b/services/core/java/com/android/server/inputmethod/HandwritingModeController.java
index d31f7c5b07df4..b301d99b00de5 100644
--- a/services/core/java/com/android/server/inputmethod/HandwritingModeController.java
+++ b/services/core/java/com/android/server/inputmethod/HandwritingModeController.java
@@ -136,7 +136,7 @@ final class HandwritingModeController {
      */
     @UiThread
     @Nullable
-    HandwritingSession startHandwritingSession(int requestId) {
+    HandwritingSession startHandwritingSession(int requestId, int imePid, int imeUid) {
         if (mHandwritingSurface == null) {
             Slog.e(TAG, "Cannot start handwriting session: Handwriting was not initialized.");
             return null;
@@ -160,7 +160,7 @@ final class HandwritingModeController {
             throw new IllegalStateException(
                     "Handwriting surface should not be already intercepting.");
         }
-        mHandwritingSurface.startIntercepting();
+        mHandwritingSurface.startIntercepting(imePid, imeUid);
 
         return new HandwritingSession(mCurrentRequestId, mHandwritingSurface.getInputChannel(),
                 mHandwritingBuffer);
diff --git a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
index eb1de2a9bf915..efe99d7611f9e 100644
--- a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
+++ b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
@@ -4702,7 +4702,10 @@ public final class InputMethodManagerService extends IInputMethodManager.Stub
                         return true;
                     }
                     final HandwritingModeController.HandwritingSession session =
-                            mHwController.startHandwritingSession(msg.arg1);
+                            mHwController.startHandwritingSession(
+                                    msg.arg1 /*requestId*/,
+                                    msg.arg2 /*pid*/,
+                                    mBindingController.getCurMethodUid());
                     if (session == null) {
                         Slog.e(TAG,
                                 "Failed to start handwriting session for requestId: " + msg.arg1);
@@ -4722,8 +4725,8 @@ public final class InputMethodManagerService extends IInputMethodManager.Stub
     }
 
     @BinderThread
-    private void onStylusHandwritingReady(int requestId) {
-        mHandler.obtainMessage(MSG_START_HANDWRITING, requestId, 0 /* unused */).sendToTarget();
+    private void onStylusHandwritingReady(int requestId, int pid) {
+        mHandler.obtainMessage(MSG_START_HANDWRITING, requestId, pid).sendToTarget();
     }
 
     private void handleSetInteractive(final boolean interactive) {
@@ -6304,8 +6307,8 @@ public final class InputMethodManagerService extends IInputMethodManager.Stub
 
         @BinderThread
         @Override
-        public void onStylusHandwritingReady(int requestId) {
-            mImms.onStylusHandwritingReady(requestId);
+        public void onStylusHandwritingReady(int requestId, int pid) {
+            mImms.onStylusHandwritingReady(requestId, pid);
         }
 
         @BinderThread