commit 46ef0f509f693419e3a549a9a3256d9280542044
author Jayant Chowdhary <jchowdhary@google.com> Tue Oct 05 14:36:13 2021 -0700
committer Jayant Chowdhary <jchowdhary@google.com> Tue Oct 12 17:14:52 2021 -0700
tree faa85cb4b659878f646d48a1a65ec2884865e3db
parent 7eb31a2523ec872575e91723d0d2da0f70c31e57

cameraserver: fix deadlock scenario in torchModeStatusChanged callback.

The following scenario can occur:

T1: CameraService::connectDevice()
      CameraService::connectDeviceHelper()
         CameraProviderManager::openSession() ---> holds mInterfaceLock
         .
         .
         . on the same thread before openSession execution completes
           CameraProviderManager::ProviderInfo::torchModeStatusChange() callback from HAL
           .
             CameraService::onTorchStatusChanged()
               CameraProviderManager::getSystemCameraKind tries to lock mInterfaceLock -> deadlock.

We now pass in system camera kind to onTorchStatusChanged in
CameraProviderManager::torchModeStatusChange() instead of calling getSystemCameraKind

This CL also removes CameraProviderManager::mStatusListenerMutex, since
it wasn't protecting any data structure.

Bug: 202198748

Test: camera CTS, GCA (basic validity)

Change-Id: Id95a2aa061b6cb4db4a25b1a2aa6a390f898af87
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>

services/camera/libcameraservice/common/CameraProviderManager.h

diff --git a/services/camera/libcameraservice/common/CameraProviderManager.h b/services/camera/libcameraservice/common/CameraProviderManager.h
index e3763a1..fdb2673 100644
--- a/services/camera/libcameraservice/common/CameraProviderManager.h
+++ b/services/camera/libcameraservice/common/CameraProviderManager.h
@@ -155,6 +155,9 @@
                 const String8 &physicalCameraId,
                 hardware::camera::common::V1_0::CameraDeviceStatus newStatus) = 0;
         virtual void onTorchStatusChanged(const String8 &cameraId,
+                hardware::camera::common::V1_0::TorchModeStatus newStatus,
+                SystemCameraKind kind) = 0;
+        virtual void onTorchStatusChanged(const String8 &cameraId,
                 hardware::camera::common::V1_0::TorchModeStatus newStatus) = 0;
         virtual void onNewProviderRegistered() = 0;
     };
@@ -329,8 +332,6 @@
     // All private members, unless otherwise noted, expect mInterfaceMutex to be locked before use
     mutable std::mutex mInterfaceMutex;
 
-    // the status listener update callbacks will lock mStatusMutex
-    mutable std::mutex mStatusListenerMutex;
     wp<StatusListener> mListener;
     ServiceInteractionProxy* mServiceProxy;