allow "system" screenshots even when the secure flag is set

we need too allow this case so that things like the rotation
animation can work.
with this change we only permit these screenshot if the
destination is SurfaceFlinger itself.

Bug: 10235036
Change-Id: I66fea5391e52b0d7f17f25827572b236f2d9eb71

1 files changed, 12 insertions, 6 deletions

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 4a84e5a530..b76cde773f 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2662,6 +2662,18 @@ status_t SurfaceFlinger::captureScreen(const sp<IBinder>& display,
     if (CC_UNLIKELY(producer == 0))
         return BAD_VALUE;
 
+    // if we have secure windows on this display, never allow the screen capture
+    // unless the producer interface is local (i.e.: we can take a screenshot for
+    // ourselves).
+    if (!producer->asBinder()->localBinder()) {
+        Mutex::Autolock _l(mStateLock);
+        sp<const DisplayDevice> hw(getDisplayDevice(display));
+        if (hw->getSecureLayerVisible()) {
+            ALOGW("FB is protected: PERMISSION_DENIED");
+            return PERMISSION_DENIED;
+        }
+    }
+
     class MessageCaptureScreen : public MessageBase {
         SurfaceFlinger* flinger;
         sp<IBinder> display;
@@ -2786,12 +2798,6 @@ status_t SurfaceFlinger::captureScreenImplLocked(
     const uint32_t hw_w = hw->getWidth();
     const uint32_t hw_h = hw->getHeight();
 
-    // if we have secure windows on this display, never allow the screen capture
-    if (hw->getSecureLayerVisible()) {
-        ALOGW("FB is protected: PERMISSION_DENIED");
-        return PERMISSION_DENIED;
-    }
-
     if ((reqWidth > hw_w) || (reqHeight > hw_h)) {
         ALOGE("size mismatch (%d, %d) > (%d, %d)",
                 reqWidth, reqHeight, hw_w, hw_h);