commit 4aa22af29dcc20801344d1af84b2a790aef29af9
author Chavi Weingarten <chaviw@google.com> Fri Nov 17 19:37:07 2023 +0000
committer Chavi Weingarten <chaviw@google.com> Tue Nov 21 16:52:36 2023 +0000
tree 373f4888c9f6b8d4bb11ec2f8312587666ef12c4
parent d1a34bff5ab6914f08110ab6c93e3919b51366b7

Ensure sub-hierarchy screenshots inherit secure from parent.

If a sub-hierarchy is screenshot that doesn't include the parent layer
that had the secure flag, the screenshot request would not respect the
secure flag. This is incorrect because we want to ensure secure flag
remains on all children regardless of where in the hierarchy the
screenshot is taken.

Test: CaptureChildRespectsParentSecureFlag
Test: CaptureOffscreenChildRespectsParentSecureFlag
Test: LayerSnapshotTest#setSecureRootSnapshot
Bug: 308662081
Change-Id: I13f19a7fa4b9e51da0aa097314f015fe1340fc54

services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp

diff --git a/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp b/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
index 9476ff4..743cbf3 100644
--- a/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
+++ b/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
@@ -365,7 +365,7 @@
     return snapshot;
 }
 
-LayerSnapshotBuilder::LayerSnapshotBuilder() : mRootSnapshot(getRootSnapshot()) {}
+LayerSnapshotBuilder::LayerSnapshotBuilder() {}
 
 LayerSnapshotBuilder::LayerSnapshotBuilder(Args args) : LayerSnapshotBuilder() {
     args.forceUpdate = ForceUpdateFlags::ALL;
@@ -417,19 +417,20 @@
 
 void LayerSnapshotBuilder::updateSnapshots(const Args& args) {
     ATRACE_NAME("UpdateSnapshots");
+    LayerSnapshot rootSnapshot = args.rootSnapshot;
     if (args.parentCrop) {
-        mRootSnapshot.geomLayerBounds = *args.parentCrop;
+        rootSnapshot.geomLayerBounds = *args.parentCrop;
     } else if (args.forceUpdate == ForceUpdateFlags::ALL || args.displayChanges) {
-        mRootSnapshot.geomLayerBounds = getMaxDisplayBounds(args.displays);
+        rootSnapshot.geomLayerBounds = getMaxDisplayBounds(args.displays);
     }
     if (args.displayChanges) {
-        mRootSnapshot.changes = RequestedLayerState::Changes::AffectsChildren |
+        rootSnapshot.changes = RequestedLayerState::Changes::AffectsChildren |
                 RequestedLayerState::Changes::Geometry;
     }
     if (args.forceUpdate == ForceUpdateFlags::HIERARCHY) {
-        mRootSnapshot.changes |=
+        rootSnapshot.changes |=
                 RequestedLayerState::Changes::Hierarchy | RequestedLayerState::Changes::Visibility;
-        mRootSnapshot.clientChanges |= layer_state_t::eReparent;
+        rootSnapshot.clientChanges |= layer_state_t::eReparent;
     }
 
     for (auto& snapshot : mSnapshots) {
@@ -444,13 +445,13 @@
         // multiple children.
         LayerHierarchy::ScopedAddToTraversalPath addChildToPath(root, args.root.getLayer()->id,
                                                                 LayerHierarchy::Variant::Attached);
-        updateSnapshotsInHierarchy(args, args.root, root, mRootSnapshot, /*depth=*/0);
+        updateSnapshotsInHierarchy(args, args.root, root, rootSnapshot, /*depth=*/0);
     } else {
         for (auto& [childHierarchy, variant] : args.root.mChildren) {
             LayerHierarchy::ScopedAddToTraversalPath addChildToPath(root,
                                                                     childHierarchy->getLayer()->id,
                                                                     variant);
-            updateSnapshotsInHierarchy(args, *childHierarchy, root, mRootSnapshot, /*depth=*/0);
+            updateSnapshotsInHierarchy(args, *childHierarchy, root, rootSnapshot, /*depth=*/0);
         }
     }
 
@@ -459,7 +460,6 @@
     updateTouchableRegionCrop(args);
 
     const bool hasUnreachableSnapshots = sortSnapshotsByZ(args);
-    clearChanges(mRootSnapshot);
 
     // Destroy unreachable snapshots for clone layers. And destroy snapshots for non-clone
     // layers if the layer have been destroyed.