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Commit 1ed8b0ba authored by Jan Sebechlebsky's avatar Jan Sebechlebsky
Browse files

Avoid nested locking when calling from VDMS to VDs. 

... to prevent lock inversion.

Bug: 276751545
Test: atest VirtualDeviceManagerServiceTest
Test: atest CtsVirtualDevicesTestCases
Change-Id: I5835e50699bf45e839cc3113555ddf71023368b0
parent 7766ef11

services/companion/java/com/android/server/companion/virtual/VirtualDeviceManagerService.java

+57 −58
Original line number Diff line number Diff line
@@ -151,17 +151,16 @@ public class VirtualDeviceManagerService extends SystemService { 
    }



    void onCameraAccessBlocked(int appUid) {

        synchronized (mVirtualDeviceManagerLock) {

            for (int i = 0; i < mVirtualDevices.size(); i++) {

                CharSequence deviceName = mVirtualDevices.valueAt(i).getDisplayName();

                mVirtualDevices.valueAt(i).showToastWhereUidIsRunning(appUid,

        ArrayList<VirtualDeviceImpl> virtualDevicesSnapshot = getVirtualDevicesSnapshot();

        for (int i = 0; i < virtualDevicesSnapshot.size(); i++) {

            VirtualDeviceImpl virtualDevice = virtualDevicesSnapshot.get(i);

            virtualDevice.showToastWhereUidIsRunning(appUid,

                    getContext().getString(

                            com.android.internal.R.string.vdm_camera_access_denied,

                                deviceName),

                            virtualDevice.getDisplayName()),

                    Toast.LENGTH_LONG, Looper.myLooper());

        }

    }

    }



    CameraAccessController getCameraAccessController(UserHandle userHandle) {

        int userId = userHandle.getIdentifier();
@@ -265,6 +264,16 @@ public class VirtualDeviceManagerService extends SystemService { 
        cdm.removeOnAssociationsChangedListener(mCdmAssociationListener);

    }



    private ArrayList<VirtualDeviceImpl> getVirtualDevicesSnapshot() {

        synchronized (mVirtualDeviceManagerLock) {

            ArrayList<VirtualDeviceImpl> virtualDevices = new ArrayList<>(mVirtualDevices.size());

            for (int i = 0; i < mVirtualDevices.size(); i++) {

                virtualDevices.add(mVirtualDevices.valueAt(i));

            }

            return virtualDevices;

        }

    }



    class VirtualDeviceManagerImpl extends IVirtualDeviceManager.Stub {



        private final VirtualDeviceImpl.PendingTrampolineCallback mPendingTrampolineCallback =
@@ -314,16 +323,6 @@ public class VirtualDeviceManagerService extends SystemService { 
            Objects.requireNonNull(activityListener);

            Objects.requireNonNull(soundEffectListener);



            synchronized (mVirtualDeviceManagerLock) {

                if (mVirtualDevices.size() == 0) {

                    final long callindId = Binder.clearCallingIdentity();

                    try {

                        registerCdmAssociationListener();

                    } finally {

                        Binder.restoreCallingIdentity(callindId);

                    }

                }



            final UserHandle userHandle = getCallingUserHandle();

            final CameraAccessController cameraAccessController =

                    getCameraAccessController(userHandle);
@@ -335,9 +334,18 @@ public class VirtualDeviceManagerService extends SystemService { 
                    deviceId, cameraAccessController,

                    mPendingTrampolineCallback, activityListener,

                    soundEffectListener, runningAppsChangedCallback, params);

            synchronized (mVirtualDeviceManagerLock) {

                if (mVirtualDevices.size() == 0) {

                    final long callindId = Binder.clearCallingIdentity();

                    try {

                        registerCdmAssociationListener();

                    } finally {

                        Binder.restoreCallingIdentity(callindId);

                    }

                }

                mVirtualDevices.put(deviceId, virtualDevice);

                return virtualDevice;

            }

            return virtualDevice;

        }



        @Override // Binder call
@@ -399,14 +407,13 @@ public class VirtualDeviceManagerService extends SystemService { 
            if (displayId == Display.INVALID_DISPLAY || displayId == Display.DEFAULT_DISPLAY) {

                return Context.DEVICE_ID_DEFAULT;

            }

            synchronized (mVirtualDeviceManagerLock) {

                for (int i = 0; i < mVirtualDevices.size(); i++) {

                    VirtualDeviceImpl virtualDevice = mVirtualDevices.valueAt(i);

            ArrayList<VirtualDeviceImpl> virtualDevicesSnapshot = getVirtualDevicesSnapshot();

            for (int i = 0; i < virtualDevicesSnapshot.size(); i++) {

                VirtualDeviceImpl virtualDevice = virtualDevicesSnapshot.get(i);

                if (virtualDevice.isDisplayOwnedByVirtualDevice(displayId)) {

                    return virtualDevice.getDeviceId();

                }

            }

            }

            return Context.DEVICE_ID_DEFAULT;

        }
@@ -496,10 +503,9 @@ public class VirtualDeviceManagerService extends SystemService { 
                return;

            }

            fout.println("Created virtual devices: ");

            synchronized (mVirtualDeviceManagerLock) {

                for (int i = 0; i < mVirtualDevices.size(); i++) {

                    mVirtualDevices.valueAt(i).dump(fd, fout, args);

                }

            ArrayList<VirtualDeviceImpl> virtualDevicesSnapshot = getVirtualDevicesSnapshot();

            for (int i = 0; i < virtualDevicesSnapshot.size(); i++) {

                virtualDevicesSnapshot.get(i).dump(fd, fout, args);

            }

        }

    }
@@ -516,35 +522,32 @@ public class VirtualDeviceManagerService extends SystemService { 


        @Override

        public int getDeviceOwnerUid(int deviceId) {

            VirtualDeviceImpl virtualDevice;

            synchronized (mVirtualDeviceManagerLock) {

                VirtualDeviceImpl virtualDevice = mVirtualDevices.get(deviceId);

                return virtualDevice != null ? virtualDevice.getOwnerUid() : Process.INVALID_UID;

                virtualDevice = mVirtualDevices.get(deviceId);

            }

            return virtualDevice != null ? virtualDevice.getOwnerUid() : Process.INVALID_UID;

        }



        @Override

        public @Nullable VirtualSensor getVirtualSensor(int deviceId, int handle) {

            VirtualDeviceImpl virtualDevice;

            synchronized (mVirtualDeviceManagerLock) {

                VirtualDeviceImpl virtualDevice = mVirtualDevices.get(deviceId);

                if (virtualDevice != null) {

                    return virtualDevice.getVirtualSensorByHandle(handle);

                virtualDevice = mVirtualDevices.get(deviceId);

            }

            }

            return null;

            return virtualDevice != null ? virtualDevice.getVirtualSensorByHandle(handle) : null;

        }



        @Override

        public @NonNull ArraySet<Integer> getDeviceIdsForUid(int uid) {

            ArrayList<VirtualDeviceImpl> virtualDevicesSnapshot = getVirtualDevicesSnapshot();

            ArraySet<Integer> result = new ArraySet<>();

            synchronized (mVirtualDeviceManagerLock) {

                int size = mVirtualDevices.size();

                for (int i = 0; i < size; i++) {

                    VirtualDeviceImpl device = mVirtualDevices.valueAt(i);

            for (int i = 0; i < virtualDevicesSnapshot.size(); i++) {

                VirtualDeviceImpl device = virtualDevicesSnapshot.get(i);

                if (device.isAppRunningOnVirtualDevice(uid)) {

                    result.add(device.getDeviceId());

                }

            }

            }

            return result;

        }
@@ -630,27 +633,23 @@ public class VirtualDeviceManagerService extends SystemService { 


        @Override

        public boolean isAppRunningOnAnyVirtualDevice(int uid) {

            synchronized (mVirtualDeviceManagerLock) {

                int size = mVirtualDevices.size();

                for (int i = 0; i < size; i++) {

                    if (mVirtualDevices.valueAt(i).isAppRunningOnVirtualDevice(uid)) {

            ArrayList<VirtualDeviceImpl> virtualDevicesSnapshot = getVirtualDevicesSnapshot();

            for (int i = 0; i < virtualDevicesSnapshot.size(); i++) {

                if (virtualDevicesSnapshot.get(i).isAppRunningOnVirtualDevice(uid)) {

                    return true;

                }

            }

            }

            return false;

        }



        @Override

        public boolean isDisplayOwnedByAnyVirtualDevice(int displayId) {

            synchronized (mVirtualDeviceManagerLock) {

                int size = mVirtualDevices.size();

                for (int i = 0; i < size; i++) {

                    if (mVirtualDevices.valueAt(i).isDisplayOwnedByVirtualDevice(displayId)) {

            ArrayList<VirtualDeviceImpl> virtualDevicesSnapshot = getVirtualDevicesSnapshot();

            for (int i = 0; i < virtualDevicesSnapshot.size(); i++) {

                if (virtualDevicesSnapshot.get(i).isDisplayOwnedByVirtualDevice(displayId)) {

                    return true;

                }

            }

            }

            return false;

        }