Add mechanism for a task's windows to be trusted overlays (SF)

- Add a layer state to indicate that this layer and its children
  in the hierarchy are trusted. This can only be set by callers
  holding ACCESS_SURFACE_FLINGER, and will be used for the PIP
  task layer to indicate that activities in PIP are trusted (as
  they are controlled only by the user and SystemUI)

Bug: 191529039
Bug: 196389741
Test: TBD

Change-Id: Id92ccb087bd0d8dbaeeef3ba50b67fe015e53db8
Merged-In: Id92ccb087bd0d8dbaeeef3ba50b67fe015e53db8
diff --git a/cmds/surfacereplayer/proto/src/trace.proto b/cmds/surfacereplayer/proto/src/trace.proto
index b574098..372cecd 100644
--- a/cmds/surfacereplayer/proto/src/trace.proto
+++ b/cmds/surfacereplayer/proto/src/trace.proto
@@ -53,6 +53,7 @@
         ReparentChildrenChange      reparent_children       = 20;
         BackgroundBlurRadiusChange  background_blur_radius  = 21;
         ShadowRadiusChange          shadow_radius           = 22;
+        TrustedOverlayChange        trusted_overlay         = 23;
     }
 }
 
@@ -208,4 +209,8 @@
 
 message ShadowRadiusChange {
     required float radius = 1;
+}
+
+message TrustedOverlayChange {
+    required float is_trusted_overlay = 1;
 }
\ No newline at end of file
diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index e43446a..a897d10 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -117,6 +117,8 @@
     output.writeFloat(frameRate);
     output.writeByte(frameRateCompatibility);
     output.writeUint32(fixedTransformHint);
+    output.writeBool(isTrustedOverlay);
+
     return NO_ERROR;
 }
 
@@ -200,6 +202,8 @@
     frameRate = input.readFloat();
     frameRateCompatibility = input.readByte();
     fixedTransformHint = static_cast<ui::Transform::RotationFlags>(input.readUint32());
+    isTrustedOverlay = input.readBool();
+
     return NO_ERROR;
 }
 
@@ -439,6 +443,10 @@
         what |= eFixedTransformHintChanged;
         fixedTransformHint = other.fixedTransformHint;
     }
+    if (other.what & eTrustedOverlayChanged) {
+        what |= eTrustedOverlayChanged;
+        isTrustedOverlay = other.isTrustedOverlay;
+    }
     if ((other.what & what) != other.what) {
         ALOGE("Unmerged SurfaceComposer Transaction properties. LayerState::merge needs updating? "
               "other.what=0x%" PRIu64 " what=0x%" PRIu64,
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 83bc069..78d932c 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -1484,6 +1484,19 @@
     return *this;
 }
 
+SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::setTrustedOverlay(
+        const sp<SurfaceControl>& sc, bool isTrustedOverlay) {
+    layer_state_t* s = getLayerState(sc);
+    if (!s) {
+        mStatus = BAD_INDEX;
+        return *this;
+    }
+
+    s->what |= layer_state_t::eTrustedOverlayChanged;
+    s->isTrustedOverlay = isTrustedOverlay;
+    return *this;
+}
+
 // ---------------------------------------------------------------------------
 
 DisplayState& SurfaceComposerClient::Transaction::getDisplayState(const sp<IBinder>& token) {
diff --git a/libs/gui/include/gui/LayerState.h b/libs/gui/include/gui/LayerState.h
index e60f677..a77e4b0 100644
--- a/libs/gui/include/gui/LayerState.h
+++ b/libs/gui/include/gui/LayerState.h
@@ -105,6 +105,7 @@
         eBackgroundBlurRadiusChanged = 0x80'00000000,
         eProducerDisconnect = 0x100'00000000,
         eFixedTransformHintChanged = 0x200'00000000,
+        eTrustedOverlayChanged = 0x400'00000000,
     };
 
     layer_state_t()
@@ -139,7 +140,8 @@
             frameRateSelectionPriority(-1),
             frameRate(0.0f),
             frameRateCompatibility(ANATIVEWINDOW_FRAME_RATE_COMPATIBILITY_DEFAULT),
-            fixedTransformHint(ui::Transform::ROT_INVALID) {
+            fixedTransformHint(ui::Transform::ROT_INVALID),
+            isTrustedOverlay(false) {
         matrix.dsdx = matrix.dtdy = 1.0f;
         matrix.dsdy = matrix.dtdx = 0.0f;
         hdrMetadata.validTypes = 0;
@@ -237,6 +239,10 @@
     // a buffer of a different size. -1 means the transform hint is not set,
     // otherwise the value will be a valid ui::Rotation.
     ui::Transform::RotationFlags fixedTransformHint;
+
+    // An inherited state that indicates that this surface control and its children
+    // should be trusted for input occlusion detection purposes
+    bool isTrustedOverlay;
 };
 
 struct ComposerState {
diff --git a/libs/gui/include/gui/SurfaceComposerClient.h b/libs/gui/include/gui/SurfaceComposerClient.h
index adcb898..eebd9ca 100644
--- a/libs/gui/include/gui/SurfaceComposerClient.h
+++ b/libs/gui/include/gui/SurfaceComposerClient.h
@@ -529,6 +529,9 @@
         // a buffer of a different size.
         Transaction& setFixedTransformHint(const sp<SurfaceControl>& sc, int32_t transformHint);
 
+        // Sets that this surface control and its children are trusted overlays for input
+        Transaction& setTrustedOverlay(const sp<SurfaceControl>& sc, bool isTrustedOverlay);
+        
         status_t setDisplaySurface(const sp<IBinder>& token,
                 const sp<IGraphicBufferProducer>& bufferProducer);
 
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 03903f6..ceea79f 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -1142,6 +1142,23 @@
     return true;
 }
 
+bool Layer::setTrustedOverlay(bool isTrustedOverlay) {
+    if (mCurrentState.isTrustedOverlay == isTrustedOverlay) return false;
+    mCurrentState.isTrustedOverlay = isTrustedOverlay;
+    mCurrentState.modified = true;
+    mCurrentState.inputInfoChanged = true;
+    setTransactionFlags(eTransactionNeeded);
+    return true;
+}
+
+bool Layer::isTrustedOverlay() const {
+    if (getDrawingState().isTrustedOverlay) {
+        return true;
+    }
+    const auto& p = mDrawingParent.promote();
+    return (p != nullptr) && p->isTrustedOverlay();
+}
+
 bool Layer::setSize(uint32_t w, uint32_t h) {
     if (mCurrentState.requested_legacy.w == w && mCurrentState.requested_legacy.h == h)
         return false;
@@ -2245,6 +2262,7 @@
         layerInfo->set_effective_scaling_mode(getEffectiveScalingMode());
 
         layerInfo->set_corner_radius(getRoundedCornerState().radius);
+        layerInfo->set_is_trusted_overlay(isTrustedOverlay());
         LayerProtoHelper::writeToProto(transform, layerInfo->mutable_transform());
         LayerProtoHelper::writePositionToProto(transform.tx(), transform.ty(),
                                                [&]() { return layerInfo->mutable_position(); });
@@ -2435,6 +2453,10 @@
         info.touchableRegion = info.touchableRegion.intersect(Rect{cropLayer->mScreenBounds});
     }
 
+    // Inherit the trusted state from the parent hierarchy, but don't clobber the trusted state
+    // if it was set by WM for a known system overlay
+    info.trustedOverlay = info.trustedOverlay || isTrustedOverlay();
+
     // If the layer is a clone, we need to crop the input region to cloned root to prevent
     // touches from going outside the cloned area.
     if (isClone()) {
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 2c90c92..a12bae4 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -279,6 +279,9 @@
         // a buffer of a different size. ui::Transform::ROT_INVALID means the
         // a fixed transform hint is not set.
         ui::Transform::RotationFlags fixedTransformHint;
+
+        // Whether or not this layer is a trusted overlay for input
+        bool isTrustedOverlay;
     };
 
     explicit Layer(const LayerCreationArgs& args);
@@ -356,6 +359,7 @@
     // is specified in pixels.
     virtual bool setBackgroundBlurRadius(int backgroundBlurRadius);
     virtual bool setTransparentRegionHint(const Region& transparent);
+    virtual bool setTrustedOverlay(bool);
     virtual bool setFlags(uint8_t flags, uint8_t mask);
     virtual bool setLayerStack(uint32_t layerStack);
     virtual uint32_t getLayerStack() const;
@@ -1064,6 +1068,7 @@
                                           const std::vector<Layer*>& layersInTree);
 
     void updateTreeHasFrameRateVote();
+    bool isTrustedOverlay() const;
 
     // Cached properties computed from drawing state
     // Effective transform taking into account parent transforms and any parent scaling.
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 4a60d5c..4947210 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3858,6 +3858,15 @@
             flags |= eTraversalNeeded | eTransformHintUpdateNeeded;
         }
     }
+    if (what & layer_state_t::eTrustedOverlayChanged) {
+        if (privileged) {
+            if (layer->setTrustedOverlay(s.isTrustedOverlay)) {
+                flags |= eTraversalNeeded;
+            }
+        } else {
+            ALOGE("Attempt to set trusted overlay without permission ACCESS_SURFACE_FLINGER");
+        }
+    }
     // This has to happen after we reparent children because when we reparent to null we remove
     // child layers from current state and remove its relative z. If the children are reparented in
     // the same transaction, then we have to make sure we reparent the children first so we do not
diff --git a/services/surfaceflinger/SurfaceInterceptor.cpp b/services/surfaceflinger/SurfaceInterceptor.cpp
index 80102bd..0555acf 100644
--- a/services/surfaceflinger/SurfaceInterceptor.cpp
+++ b/services/surfaceflinger/SurfaceInterceptor.cpp
@@ -130,6 +130,7 @@
                             getLayerIdFromWeakRef(layer->mCurrentState.zOrderRelativeOf),
                             layer->mCurrentState.z);
     addShadowRadiusLocked(transaction, layerId, layer->mCurrentState.shadowRadius);
+    addTrustedOverlayLocked(transaction, layerId, layer->mDrawingState.isTrustedOverlay);
 }
 
 void SurfaceInterceptor::addInitialDisplayStateLocked(Increment* increment,
@@ -388,6 +389,13 @@
     overrideChange->set_radius(shadowRadius);
 }
 
+void SurfaceInterceptor::addTrustedOverlayLocked(Transaction* transaction, int32_t layerId,
+                                                 bool isTrustedOverlay) {
+    SurfaceChange* change(createSurfaceChangeLocked(transaction, layerId));
+    TrustedOverlayChange* overrideChange(change->mutable_trusted_overlay());
+    overrideChange->set_is_trusted_overlay(isTrustedOverlay);
+}
+
 void SurfaceInterceptor::addSurfaceChangesLocked(Transaction* transaction,
         const layer_state_t& state)
 {
@@ -467,6 +475,9 @@
     if (state.what & layer_state_t::eShadowRadiusChanged) {
         addShadowRadiusLocked(transaction, layerId, state.shadowRadius);
     }
+    if (state.what & layer_state_t::eTrustedOverlayChanged) {
+        addTrustedOverlayLocked(transaction, layerId, state.isTrustedOverlay);
+    }
 }
 
 void SurfaceInterceptor::addDisplayChangesLocked(Transaction* transaction,
diff --git a/services/surfaceflinger/SurfaceInterceptor.h b/services/surfaceflinger/SurfaceInterceptor.h
index 896bdcc..6b98b44 100644
--- a/services/surfaceflinger/SurfaceInterceptor.h
+++ b/services/surfaceflinger/SurfaceInterceptor.h
@@ -168,6 +168,7 @@
     void addRelativeParentLocked(Transaction* transaction, int32_t layerId, int32_t parentId,
                                  int z);
     void addShadowRadiusLocked(Transaction* transaction, int32_t layerId, float shadowRadius);
+    void addTrustedOverlayLocked(Transaction* transaction, int32_t layerId, bool isTrustedOverlay);
 
     // Add display transactions to the trace
     DisplayChange* createDisplayChangeLocked(Transaction* transaction, int32_t sequenceId);
diff --git a/services/surfaceflinger/layerproto/LayerProtoParser.cpp b/services/surfaceflinger/layerproto/LayerProtoParser.cpp
index 8fce0c9..2eceba8 100644
--- a/services/surfaceflinger/layerproto/LayerProtoParser.cpp
+++ b/services/surfaceflinger/layerproto/LayerProtoParser.cpp
@@ -105,6 +105,7 @@
     layer.queuedFrames = layerProto.queued_frames();
     layer.refreshPending = layerProto.refresh_pending();
     layer.isProtected = layerProto.is_protected();
+    layer.isTrustedOverlay = layerProto.is_trusted_overlay();
     layer.cornerRadius = layerProto.corner_radius();
     layer.backgroundBlurRadius = layerProto.background_blur_radius();
     for (const auto& entry : layerProto.metadata()) {
@@ -288,6 +289,7 @@
     StringAppendF(&result, "crop=%s, ", crop.to_string().c_str());
     StringAppendF(&result, "cornerRadius=%f, ", cornerRadius);
     StringAppendF(&result, "isProtected=%1d, ", isProtected);
+    StringAppendF(&result, "isTrustedOverlay=%1d, ", isTrustedOverlay);
     StringAppendF(&result, "isOpaque=%1d, invalidate=%1d, ", isOpaque, invalidate);
     StringAppendF(&result, "dataspace=%s, ", dataspace.c_str());
     StringAppendF(&result, "defaultPixelFormat=%s, ", pixelFormat.c_str());
diff --git a/services/surfaceflinger/layerproto/include/layerproto/LayerProtoParser.h b/services/surfaceflinger/layerproto/include/layerproto/LayerProtoParser.h
index 52b9165..67bbd76 100644
--- a/services/surfaceflinger/layerproto/include/layerproto/LayerProtoParser.h
+++ b/services/surfaceflinger/layerproto/include/layerproto/LayerProtoParser.h
@@ -109,6 +109,7 @@
         int32_t queuedFrames;
         bool refreshPending;
         bool isProtected;
+        bool isTrustedOverlay;
         float cornerRadius;
         int backgroundBlurRadius;
         LayerMetadata metadata;
diff --git a/services/surfaceflinger/layerproto/layers.proto b/services/surfaceflinger/layerproto/layers.proto
index 7f1f542..780b066 100644
--- a/services/surfaceflinger/layerproto/layers.proto
+++ b/services/surfaceflinger/layerproto/layers.proto
@@ -123,6 +123,8 @@
   bool is_relative_of = 51;
   // Layer's background blur radius in pixels.
   int32 background_blur_radius = 52;
+
+  bool is_trusted_overlay = 53;
 }
 
 message PositionProto {
diff --git a/services/surfaceflinger/tests/SurfaceInterceptor_test.cpp b/services/surfaceflinger/tests/SurfaceInterceptor_test.cpp
index 8d97f27..5bafbd8 100644
--- a/services/surfaceflinger/tests/SurfaceInterceptor_test.cpp
+++ b/services/surfaceflinger/tests/SurfaceInterceptor_test.cpp
@@ -195,6 +195,7 @@
     bool detachChildrenUpdateFound(const SurfaceChange& change, bool found);
     bool reparentChildrenUpdateFound(const SurfaceChange& change, bool found);
     bool shadowRadiusUpdateFound(const SurfaceChange& change, bool found);
+    bool trustedOverlayUpdateFound(const SurfaceChange& change, bool found);
     bool surfaceUpdateFound(const Trace& trace, SurfaceChange::SurfaceChangeCase changeCase);
 
     // Find all of the updates in the single trace
@@ -233,6 +234,7 @@
     void detachChildrenUpdate(Transaction&);
     void reparentChildrenUpdate(Transaction&);
     void shadowRadiusUpdate(Transaction&);
+    void trustedOverlayUpdate(Transaction&);
     void surfaceCreation(Transaction&);
     void displayCreation(Transaction&);
     void displayDeletion(Transaction&);
@@ -421,6 +423,10 @@
     t.setShadowRadius(mBGSurfaceControl, SHADOW_RADIUS_UPDATE);
 }
 
+void SurfaceInterceptorTest::trustedOverlayUpdate(Transaction& t) {
+    t.setTrustedOverlay(mBGSurfaceControl, true);
+}
+
 void SurfaceInterceptorTest::displayCreation(Transaction&) {
     sp<IBinder> testDisplay = SurfaceComposerClient::createDisplay(DISPLAY_NAME, true);
     SurfaceComposerClient::destroyDisplay(testDisplay);
@@ -452,6 +458,7 @@
     runInTransaction(&SurfaceInterceptorTest::detachChildrenUpdate);
     runInTransaction(&SurfaceInterceptorTest::relativeParentUpdate);
     runInTransaction(&SurfaceInterceptorTest::shadowRadiusUpdate);
+    runInTransaction(&SurfaceInterceptorTest::trustedOverlayUpdate);
 }
 
 void SurfaceInterceptorTest::surfaceCreation(Transaction&) {
@@ -695,6 +702,17 @@
     return foundShadowRadius;
 }
 
+bool SurfaceInterceptorTest::trustedOverlayUpdateFound(const SurfaceChange& change,
+                                                       bool foundTrustedOverlay) {
+    bool hasTrustedOverlay(change.trusted_overlay().is_trusted_overlay());
+    if (hasTrustedOverlay && !foundTrustedOverlay) {
+        foundTrustedOverlay = true;
+    } else if (hasTrustedOverlay && foundTrustedOverlay) {
+        []() { FAIL(); }();
+    }
+    return foundTrustedOverlay;
+}
+
 bool SurfaceInterceptorTest::surfaceUpdateFound(const Trace& trace,
         SurfaceChange::SurfaceChangeCase changeCase) {
     bool foundUpdate = false;
@@ -764,6 +782,9 @@
                         case SurfaceChange::SurfaceChangeCase::kShadowRadius:
                             foundUpdate = shadowRadiusUpdateFound(change, foundUpdate);
                             break;
+                        case SurfaceChange::SurfaceChangeCase::kTrustedOverlay:
+                            foundUpdate = trustedOverlayUpdateFound(change, foundUpdate);
+                            break;
                         case SurfaceChange::SurfaceChangeCase::SURFACECHANGE_NOT_SET:
                             break;
                     }
@@ -976,6 +997,11 @@
                 SurfaceChange::SurfaceChangeCase::kShadowRadius);
 }
 
+TEST_F(SurfaceInterceptorTest, InterceptTrustedOverlayUpdateWorks) {
+    captureTest(&SurfaceInterceptorTest::trustedOverlayUpdate,
+                SurfaceChange::SurfaceChangeCase::kTrustedOverlay);
+}
+
 TEST_F(SurfaceInterceptorTest, InterceptAllUpdatesWorks) {
     captureTest(&SurfaceInterceptorTest::runAllUpdates,
                 &SurfaceInterceptorTest::assertAllUpdatesFound);