From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Matt Pietal Date: Fri, 1 Oct 2021 11:03:16 -0400 Subject: [PATCH] Keyguard - Treat messsages to lock with priority When switching users and attempting to lock the device, the sysui main thread becomes overwhelmed with events, creating a significant lag between the time a message is posted and processed on the main thread. This can be dangerous when these events are critical for security, such as calls coming from PhoneWindowManager#lockNow() that call KeyguardViewMediator#doKeyguardTimeout(). On older devices with slower CPUs and less memory, the delay in processing can be significant (15 - 30s). The result of not prioritizing these events leads to a window of time where a guest user can switch back to the owner, and gain access to the owner's homescreen without needing to unlock the device with the owner's credentials. As a mitigation, prioritize two events originating in two specific methods to make sure the device locks as soon as possible as well as have the system server preemptively update its local cache. Bug: 151095871 Test: Very manual race condition - follow steps listed in bug Change-Id: I7585a0a5eeb308e0e32a4f77f581556d883b5cda Merged-In: I7585a0a5eeb308e0e32a4f77f581556d883b5cda (cherry picked from commit 28c53ab8bca26af58b45625c1ebba8b9051c107d) (cherry picked from commit 563fdf4259d0e28fd960acbb63431e146707d11b) Merged-In: I7585a0a5eeb308e0e32a4f77f581556d883b5cda --- .../internal/policy/IKeyguardStateCallback.aidl | 2 +- .../systemui/keyguard/KeyguardViewMediator.java | 16 +++++++++++----- .../policy/keyguard/KeyguardServiceWrapper.java | 6 ++++++ .../policy/keyguard/KeyguardStateMonitor.java | 8 +++++++- 4 files changed, 25 insertions(+), 7 deletions(-) diff --git a/core/java/com/android/internal/policy/IKeyguardStateCallback.aidl b/core/java/com/android/internal/policy/IKeyguardStateCallback.aidl index 8e454db4cb04..a8003a1169e9 100644 --- a/core/java/com/android/internal/policy/IKeyguardStateCallback.aidl +++ b/core/java/com/android/internal/policy/IKeyguardStateCallback.aidl @@ -16,7 +16,7 @@ package com.android.internal.policy; interface IKeyguardStateCallback { - void onShowingStateChanged(boolean showing); + void onShowingStateChanged(boolean showing, int userId); void onSimSecureStateChanged(boolean simSecure); void onInputRestrictedStateChanged(boolean inputRestricted); void onTrustedChanged(boolean trusted); diff --git a/packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java b/packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java index 305370d5964b..bac481c8e478 100644 --- a/packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java +++ b/packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java @@ -1291,7 +1291,9 @@ public class KeyguardViewMediator extends SystemUI { public void doKeyguardTimeout(Bundle options) { mHandler.removeMessages(KEYGUARD_TIMEOUT); Message msg = mHandler.obtainMessage(KEYGUARD_TIMEOUT, options); - mHandler.sendMessage(msg); + // Treat these messages with priority - A call to timeout means the device should lock + // as soon as possible and not wait for other messages on the thread to process first. + mHandler.sendMessageAtFrontOfQueue(msg); } /** @@ -1488,12 +1490,15 @@ public class KeyguardViewMediator extends SystemUI { * @see #handleShow */ private void showLocked(Bundle options) { - Trace.beginSection("KeyguardViewMediator#showLocked aqcuiring mShowKeyguardWakeLock"); + Trace.beginSection("KeyguardViewMediator#showLocked acquiring mShowKeyguardWakeLock"); if (DEBUG) Log.d(TAG, "showLocked"); // ensure we stay awake until we are finished displaying the keyguard mShowKeyguardWakeLock.acquire(); Message msg = mHandler.obtainMessage(SHOW, options); - mHandler.sendMessage(msg); + // Treat these messages with priority - This call can originate from #doKeyguardTimeout, + // meaning the device should lock as soon as possible and not wait for other messages on + // the thread to process first. + mHandler.sendMessageAtFrontOfQueue(msg); Trace.endSection(); } @@ -1652,6 +1657,7 @@ public class KeyguardViewMediator extends SystemUI { case KEYGUARD_TIMEOUT: synchronized (KeyguardViewMediator.this) { doKeyguardLocked((Bundle) msg.obj); + notifyDefaultDisplayCallbacks(mShowing); } break; case DISMISS: @@ -2213,7 +2219,7 @@ public class KeyguardViewMediator extends SystemUI { for (int i = size - 1; i >= 0; i--) { IKeyguardStateCallback callback = mKeyguardStateCallbacks.get(i); try { - callback.onShowingStateChanged(showing); + callback.onShowingStateChanged(showing, KeyguardUpdateMonitor.getCurrentUser()); } catch (RemoteException e) { Slog.w(TAG, "Failed to call onShowingStateChanged", e); if (e instanceof DeadObjectException) { @@ -2261,7 +2267,7 @@ public class KeyguardViewMediator extends SystemUI { mKeyguardStateCallbacks.add(callback); try { callback.onSimSecureStateChanged(mUpdateMonitor.isSimPinSecure()); - callback.onShowingStateChanged(mShowing); + callback.onShowingStateChanged(mShowing, KeyguardUpdateMonitor.getCurrentUser()); callback.onInputRestrictedStateChanged(mInputRestricted); callback.onTrustedChanged(mUpdateMonitor.getUserHasTrust( KeyguardUpdateMonitor.getCurrentUser())); diff --git a/services/core/java/com/android/server/policy/keyguard/KeyguardServiceWrapper.java b/services/core/java/com/android/server/policy/keyguard/KeyguardServiceWrapper.java index 4e848686254a..cf5c587e0494 100644 --- a/services/core/java/com/android/server/policy/keyguard/KeyguardServiceWrapper.java +++ b/services/core/java/com/android/server/policy/keyguard/KeyguardServiceWrapper.java @@ -192,6 +192,12 @@ public class KeyguardServiceWrapper implements IKeyguardService { @Override // Binder interface public void doKeyguardTimeout(Bundle options) { + int userId = mKeyguardStateMonitor.getCurrentUser(); + if (mKeyguardStateMonitor.isSecure(userId)) { + // Preemptively inform the cache that the keyguard will soon be showing, as calls to + // doKeyguardTimeout are a signal to lock the device as soon as possible. + mKeyguardStateMonitor.onShowingStateChanged(true, userId); + } try { mService.doKeyguardTimeout(options); } catch (RemoteException e) { diff --git a/services/core/java/com/android/server/policy/keyguard/KeyguardStateMonitor.java b/services/core/java/com/android/server/policy/keyguard/KeyguardStateMonitor.java index dbf96aa9eee6..c49c31d2ce07 100644 --- a/services/core/java/com/android/server/policy/keyguard/KeyguardStateMonitor.java +++ b/services/core/java/com/android/server/policy/keyguard/KeyguardStateMonitor.java @@ -92,8 +92,14 @@ public class KeyguardStateMonitor extends IKeyguardStateCallback.Stub { return mHasLockscreenWallpaper; } + public int getCurrentUser() { + return mCurrentUserId; + } + @Override // Binder interface - public void onShowingStateChanged(boolean showing) { + public void onShowingStateChanged(boolean showing, int userId) { + if (userId != mCurrentUserId) return; + mIsShowing = showing; mCallback.onShowingChanged();