Merge "Add robustness for permissions errors to Surface APIs." into sc-dev

3 files changed, 15 insertions, 12 deletions

diff --git a/libs/gui/Surface.cpp b/libs/gui/Surface.cpp
index d27d1ecdbe..e117d1189c 100644
--- a/libs/gui/Surface.cpp
+++ b/libs/gui/Surface.cpp
@@ -1268,8 +1268,11 @@ int Surface::query(int what, int* value) const {
                 if (err == NO_ERROR) {
                     return NO_ERROR;
                 }
-                if (composerService()->authenticateSurfaceTexture(
-                        mGraphicBufferProducer)) {
+                sp<ISurfaceComposer> surfaceComposer = composerService();
+                if (surfaceComposer == nullptr) {
+                    return -EPERM; // likely permissions error
+                }
+                if (surfaceComposer->authenticateSurfaceTexture(mGraphicBufferProducer)) {
                     *value = 1;
                 } else {
                     *value = 0;
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 80ff653d1e..371454a3de 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -65,12 +65,12 @@ ComposerService::ComposerService()
     connectLocked();
 }
 
-void ComposerService::connectLocked() {
+bool ComposerService::connectLocked() {
     const String16 name("SurfaceFlinger");
-    while (getService(name, &mComposerService) != NO_ERROR) {
-        usleep(250000);
+    mComposerService = waitForService<ISurfaceComposer>(name);
+    if (mComposerService == nullptr) {
+        return false; // fatal error or permission problem
     }
-    assert(mComposerService != nullptr);
 
     // Create the death listener.
     class DeathObserver : public IBinder::DeathRecipient {
@@ -86,15 +86,16 @@ void ComposerService::connectLocked() {
 
     mDeathObserver = new DeathObserver(*const_cast<ComposerService*>(this));
     IInterface::asBinder(mComposerService)->linkToDeath(mDeathObserver);
+    return true;
 }
 
 /*static*/ sp<ISurfaceComposer> ComposerService::getComposerService() {
     ComposerService& instance = ComposerService::getInstance();
     Mutex::Autolock _l(instance.mLock);
     if (instance.mComposerService == nullptr) {
-        ComposerService::getInstance().connectLocked();
-        assert(instance.mComposerService != nullptr);
-        ALOGD("ComposerService reconnected");
+        if (ComposerService::getInstance().connectLocked()) {
+            ALOGD("ComposerService reconnected");
+        }
     }
     return instance.mComposerService;
 }
diff --git a/libs/gui/include/private/gui/ComposerService.h b/libs/gui/include/private/gui/ComposerService.h
index 50bd742b6a..fa1071a4e3 100644
--- a/libs/gui/include/private/gui/ComposerService.h
+++ b/libs/gui/include/private/gui/ComposerService.h
@@ -45,13 +45,12 @@ class ComposerService : public Singleton<ComposerService>
     Mutex mLock;
 
     ComposerService();
-    void connectLocked();
+    bool connectLocked();
     void composerServiceDied();
     friend class Singleton<ComposerService>;
 public:
-
     // Get a connection to the Composer Service.  This will block until
-    // a connection is established.
+    // a connection is established. Returns null if permission is denied.
     static sp<ISurfaceComposer> getComposerService();
 };