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
Test: TBD

Change-Id: Id92ccb087bd0d8dbaeeef3ba50b67fe015e53db8

14 files changed, 113 insertions, 0 deletions

diff --git a/cmds/surfacereplayer/proto/src/trace.proto b/cmds/surfacereplayer/proto/src/trace.proto
index 3798ba73a4..03a2709075 100644
--- a/cmds/surfacereplayer/proto/src/trace.proto
+++ b/cmds/surfacereplayer/proto/src/trace.proto
@@ -52,6 +52,7 @@ message SurfaceChange {
         BackgroundBlurRadiusChange  background_blur_radius  = 20;
         ShadowRadiusChange          shadow_radius           = 21;
         BlurRegionsChange           blur_regions            = 22;
+        TrustedOverlayChange        trusted_overlay         = 23;
     }
 }
 
@@ -192,6 +193,10 @@ message ShadowRadiusChange {
     required float radius = 1;
 }
 
+message TrustedOverlayChange {
+    required float is_trusted_overlay = 1;
+}
+
 message BlurRegionsChange {
     repeated BlurRegionChange blur_regions = 1;
 }
diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index 2d99fc1903..076c90dd23 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -64,6 +64,7 @@ layer_state_t::layer_state_t()
         fixedTransformHint(ui::Transform::ROT_INVALID),
         frameNumber(0),
         autoRefresh(false),
+        isTrustedOverlay(false),
         bufferCrop(Rect::INVALID_RECT),
         destinationFrame(Rect::INVALID_RECT),
         releaseBufferListener(nullptr) {
@@ -170,6 +171,7 @@ status_t layer_state_t::write(Parcel& output) const
     SAFE_PARCEL(output.write, stretchEffect);
     SAFE_PARCEL(output.write, bufferCrop);
     SAFE_PARCEL(output.write, destinationFrame);
+    SAFE_PARCEL(output.writeBool, isTrustedOverlay);
 
     return NO_ERROR;
 }
@@ -300,6 +302,7 @@ status_t layer_state_t::read(const Parcel& input)
     SAFE_PARCEL(input.read, stretchEffect);
     SAFE_PARCEL(input.read, bufferCrop);
     SAFE_PARCEL(input.read, destinationFrame);
+    SAFE_PARCEL(input.readBool, &isTrustedOverlay);
 
     return NO_ERROR;
 }
@@ -532,6 +535,10 @@ void layer_state_t::merge(const layer_state_t& other) {
         what |= eAutoRefreshChanged;
         autoRefresh = other.autoRefresh;
     }
+    if (other.what & eTrustedOverlayChanged) {
+        what |= eTrustedOverlayChanged;
+        isTrustedOverlay = other.isTrustedOverlay;
+    }
     if (other.what & eReleaseBufferListenerChanged) {
         if (releaseBufferListener) {
             ALOGW("Overriding releaseBufferListener");
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 6ea070ea2f..96da8efd19 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -1656,6 +1656,19 @@ SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::setAutoR
     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;
+}
+
 SurfaceComposerClient::Transaction& SurfaceComposerClient::Transaction::setApplyToken(
         const sp<IBinder>& applyToken) {
     mApplyToken = applyToken;
diff --git a/libs/gui/include/gui/LayerState.h b/libs/gui/include/gui/LayerState.h
index 465e34ca33..3e57ff611e 100644
--- a/libs/gui/include/gui/LayerState.h
+++ b/libs/gui/include/gui/LayerState.h
@@ -118,6 +118,7 @@ struct layer_state_t {
         eBlurRegionsChanged = 0x800'00000000,
         eAutoRefreshChanged = 0x1000'00000000,
         eStretchChanged = 0x2000'00000000,
+        eTrustedOverlayChanged = 0x4000'00000000,
     };
 
     layer_state_t();
@@ -225,6 +226,10 @@ struct layer_state_t {
     // in shared buffer mode.
     bool autoRefresh;
 
+    // An inherited state that indicates that this surface control and its children
+    // should be trusted for input occlusion detection purposes
+    bool isTrustedOverlay;
+
     // Stretch effect to be applied to this layer
     StretchEffect stretchEffect;
 
diff --git a/libs/gui/include/gui/SurfaceComposerClient.h b/libs/gui/include/gui/SurfaceComposerClient.h
index c2963b58df..baa0567617 100644
--- a/libs/gui/include/gui/SurfaceComposerClient.h
+++ b/libs/gui/include/gui/SurfaceComposerClient.h
@@ -537,6 +537,9 @@ public:
         // in shared buffer mode.
         Transaction& setAutoRefresh(const sp<SurfaceControl>& sc, bool autoRefresh);
 
+        // Sets that this surface control and its children are trusted overlays for input
+        Transaction& setTrustedOverlay(const sp<SurfaceControl>& sc, bool isTrustedOverlay);
+
         // Queues up transactions using this token in SurfaceFlinger.  By default, all transactions
         // from a client are placed on the same queue. This can be used to prevent multiple
         // transactions from blocking each other.
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index e2b6a36794..dbd2793276 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -851,6 +851,23 @@ bool Layer::setRelativeLayer(const sp<IBinder>& relativeToHandle, int32_t relati
     return true;
 }
 
+bool Layer::setTrustedOverlay(bool isTrustedOverlay) {
+    if (mDrawingState.isTrustedOverlay == isTrustedOverlay) return false;
+    mDrawingState.isTrustedOverlay = isTrustedOverlay;
+    mDrawingState.modified = true;
+    mFlinger->mInputInfoChanged = 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 (mDrawingState.requested_legacy.w == w && mDrawingState.requested_legacy.h == h)
         return false;
@@ -2041,6 +2058,7 @@ void Layer::writeToProtoDrawingState(LayerProto* layerInfo, uint32_t traceFlags,
 
         layerInfo->set_corner_radius(getRoundedCornerState().radius);
         layerInfo->set_background_blur_radius(getBackgroundBlurRadius());
+        layerInfo->set_is_trusted_overlay(isTrustedOverlay());
         LayerProtoHelper::writeToProto(transform, layerInfo->mutable_transform());
         LayerProtoHelper::writePositionToProto(transform.tx(), transform.ty(),
                                                [&]() { return layerInfo->mutable_position(); });
@@ -2327,6 +2345,11 @@ InputWindowInfo Layer::fillInputInfo(const sp<DisplayDevice>& display) {
                 toPhysicalDisplay.transform(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 6b56b2d924..c5cb17ffc7 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -275,6 +275,9 @@ public:
         // Stretch effect to apply to this layer
         StretchEffect stretchEffect;
 
+        // Whether or not this layer is a trusted overlay for input
+        bool isTrustedOverlay;
+
         Rect bufferCrop;
         Rect destinationFrame;
     };
@@ -393,6 +396,7 @@ public:
     virtual bool setBackgroundBlurRadius(int backgroundBlurRadius);
     virtual bool setBlurRegions(const std::vector<BlurRegion>& effectRegions);
     virtual bool setTransparentRegionHint(const Region& transparent);
+    virtual bool setTrustedOverlay(bool);
     virtual bool setFlags(uint32_t flags, uint32_t mask);
     virtual bool setLayerStack(uint32_t layerStack);
     virtual uint32_t getLayerStack() const;
@@ -1050,6 +1054,7 @@ private:
 
     void updateTreeHasFrameRateVote();
     void setZOrderRelativeOf(const wp<Layer>& relativeOf);
+    bool isTrustedOverlay() const;
 
     // Find the root of the cloned hierarchy, this means the first non cloned parent.
     // This will return null if first non cloned parent is not found.
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 2cc810986f..f44ae71896 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4156,6 +4156,15 @@ uint32_t SurfaceFlinger::setClientStateLocked(
     if (what & layer_state_t::eAutoRefreshChanged) {
         layer->setAutoRefresh(s.autoRefresh);
     }
+    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");
+        }
+    }
     if (what & layer_state_t::eStretchChanged) {
         if (layer->setStretchEffect(s.stretchEffect)) {
             flags |= eTraversalNeeded;
diff --git a/services/surfaceflinger/SurfaceInterceptor.cpp b/services/surfaceflinger/SurfaceInterceptor.cpp
index 8ca241e53d..23ab7c8bab 100644
--- a/services/surfaceflinger/SurfaceInterceptor.cpp
+++ b/services/surfaceflinger/SurfaceInterceptor.cpp
@@ -149,6 +149,7 @@ void SurfaceInterceptor::addInitialSurfaceStateLocked(Increment* increment,
                             getLayerIdFromWeakRef(layer->mDrawingState.zOrderRelativeOf),
                             layer->mDrawingState.z);
     addShadowRadiusLocked(transaction, layerId, layer->mDrawingState.shadowRadius);
+    addTrustedOverlayLocked(transaction, layerId, layer->mDrawingState.isTrustedOverlay);
 }
 
 void SurfaceInterceptor::addInitialDisplayStateLocked(Increment* increment,
@@ -397,6 +398,13 @@ void SurfaceInterceptor::addShadowRadiusLocked(Transaction* transaction, int32_t
     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)
 {
@@ -460,6 +468,9 @@ void SurfaceInterceptor::addSurfaceChangesLocked(Transaction* transaction,
     if (state.what & layer_state_t::eShadowRadiusChanged) {
         addShadowRadiusLocked(transaction, layerId, state.shadowRadius);
     }
+    if (state.what & layer_state_t::eTrustedOverlayChanged) {
+        addTrustedOverlayLocked(transaction, layerId, state.isTrustedOverlay);
+    }
     if (state.what & layer_state_t::eStretchChanged) {
         ALOGW("SurfaceInterceptor not implemented for eStretchChanged");
     }
diff --git a/services/surfaceflinger/SurfaceInterceptor.h b/services/surfaceflinger/SurfaceInterceptor.h
index 30aca8340e..673f9e789d 100644
--- a/services/surfaceflinger/SurfaceInterceptor.h
+++ b/services/surfaceflinger/SurfaceInterceptor.h
@@ -177,6 +177,7 @@ private:
     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 aef670da33..2841f7c2fd 100644
--- a/services/surfaceflinger/layerproto/LayerProtoParser.cpp
+++ b/services/surfaceflinger/layerproto/LayerProtoParser.cpp
@@ -105,6 +105,7 @@ LayerProtoParser::Layer LayerProtoParser::generateLayer(const LayerProto& layerP
     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()) {
@@ -289,6 +290,7 @@ std::string LayerProtoParser::Layer::to_string() const {
     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 c48354fe95..52503bad3a 100644
--- a/services/surfaceflinger/layerproto/include/layerproto/LayerProtoParser.h
+++ b/services/surfaceflinger/layerproto/include/layerproto/LayerProtoParser.h
@@ -109,6 +109,7 @@ public:
         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 9f25674f1b..dddc677715 100644
--- a/services/surfaceflinger/layerproto/layers.proto
+++ b/services/surfaceflinger/layerproto/layers.proto
@@ -128,6 +128,8 @@ message LayerProto {
 
   // Regions of a layer, where blur should be applied.
   repeated BlurRegion blur_regions = 54;
+
+  bool is_trusted_overlay = 55;
 }
 
 message PositionProto {
diff --git a/services/surfaceflinger/tests/SurfaceInterceptor_test.cpp b/services/surfaceflinger/tests/SurfaceInterceptor_test.cpp
index ee4e863474..d5890ffa79 100644
--- a/services/surfaceflinger/tests/SurfaceInterceptor_test.cpp
+++ b/services/surfaceflinger/tests/SurfaceInterceptor_test.cpp
@@ -193,6 +193,7 @@ public:
     bool reparentUpdateFound(const SurfaceChange& change, bool found);
     bool relativeParentUpdateFound(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
@@ -228,6 +229,7 @@ public:
     void reparentUpdate(Transaction&);
     void relativeParentUpdate(Transaction&);
     void shadowRadiusUpdate(Transaction&);
+    void trustedOverlayUpdate(Transaction&);
     void surfaceCreation(Transaction&);
     void displayCreation(Transaction&);
     void displayDeletion(Transaction&);
@@ -405,6 +407,10 @@ void SurfaceInterceptorTest::shadowRadiusUpdate(Transaction& t) {
     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, false);
     SurfaceComposerClient::destroyDisplay(testDisplay);
@@ -433,6 +439,7 @@ void SurfaceInterceptorTest::runAllUpdates() {
     runInTransaction(&SurfaceInterceptorTest::reparentUpdate);
     runInTransaction(&SurfaceInterceptorTest::relativeParentUpdate);
     runInTransaction(&SurfaceInterceptorTest::shadowRadiusUpdate);
+    runInTransaction(&SurfaceInterceptorTest::trustedOverlayUpdate);
 }
 
 void SurfaceInterceptorTest::surfaceCreation(Transaction&) {
@@ -644,6 +651,17 @@ bool SurfaceInterceptorTest::shadowRadiusUpdateFound(const SurfaceChange& change
     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;
@@ -704,6 +722,9 @@ bool SurfaceInterceptorTest::surfaceUpdateFound(const Trace& trace,
                         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;
                     }
@@ -897,6 +918,11 @@ TEST_F(SurfaceInterceptorTest, InterceptShadowRadiusUpdateWorks) {
                 SurfaceChange::SurfaceChangeCase::kShadowRadius);
 }
 
+TEST_F(SurfaceInterceptorTest, InterceptTrustedOverlayUpdateWorks) {
+    captureTest(&SurfaceInterceptorTest::trustedOverlayUpdate,
+                SurfaceChange::SurfaceChangeCase::kTrustedOverlay);
+}
+
 TEST_F(SurfaceInterceptorTest, InterceptAllUpdatesWorks) {
     captureTest(&SurfaceInterceptorTest::runAllUpdates,
                 &SurfaceInterceptorTest::assertAllUpdatesFound);