commit 91b1df2ff45e4ab1db0c7fe80287d0b2faa09e77
author Peiyong Lin <lpy@google.com> Mon Jun 18 18:00:16 2018 -0700
committer Peiyong Lin <lpy@google.com> Tue Jun 19 13:26:20 2018 -0700
tree 276314a21cd6869af68b3aa62daffbe8620fc55c
parent 5d51a061ead239c49e9a7fef2159adb00dddad21

[SurfaceFlinger] Checking nullptr for HWC layer.

There were several places where we didn't check nullptr when accessing HWC
layer, which results in function call on nullptr when external display was
disconnected. This patch makes sure we check HWC layer before calling functions
on it.

BUG: 80325674
Test: Build, flash, boot, watch videos
Change-Id: I302ad4eeea5c196daadcdccb596dac60b02d3845

services/surfaceflinger/BufferLayer.cpp

diff --git a/services/surfaceflinger/BufferLayer.cpp b/services/surfaceflinger/BufferLayer.cpp
index 133e8f7..df6404a 100644
--- a/services/surfaceflinger/BufferLayer.cpp
+++ b/services/surfaceflinger/BufferLayer.cpp
@@ -613,6 +613,11 @@
     const auto& viewport = display->getViewport();
     Region visible = tr.transform(visibleRegion.intersect(viewport));
     const auto displayId = display->getId();
+    if (!hasHwcLayer(displayId)) {
+        ALOGE("[%s] failed to setPerFrameData: no HWC layer found (%d)",
+              mName.string(), displayId);
+        return;
+    }
     auto& hwcInfo = getBE().mHwcLayers[displayId];
     auto& hwcLayer = hwcInfo.layer;
     auto error = hwcLayer->setVisibleRegion(visible);
@@ -667,8 +672,7 @@
 
     uint32_t hwcSlot = 0;
     sp<GraphicBuffer> hwcBuffer;
-    getBE().mHwcLayers[displayId].bufferCache.getHwcBuffer(mActiveBufferSlot, mActiveBuffer,
-                                                           &hwcSlot, &hwcBuffer);
+    hwcInfo.bufferCache.getHwcBuffer(mActiveBufferSlot, mActiveBuffer, &hwcSlot, &hwcBuffer);
 
     auto acquireFence = mConsumer->getCurrentFence();
     error = hwcLayer->setBuffer(hwcSlot, hwcBuffer, acquireFence);

services/surfaceflinger/ColorLayer.cpp

diff --git a/services/surfaceflinger/ColorLayer.cpp b/services/surfaceflinger/ColorLayer.cpp
index ab8afb6..aebe4ea 100644
--- a/services/surfaceflinger/ColorLayer.cpp
+++ b/services/surfaceflinger/ColorLayer.cpp
@@ -66,6 +66,11 @@
     const auto& viewport = display->getViewport();
     Region visible = tr.transform(visibleRegion.intersect(viewport));
     const auto displayId = display->getId();
+    if (!hasHwcLayer(displayId)) {
+        ALOGE("[%s] failed to setPerFrameData: no HWC layer found (%d)",
+              mName.string(), displayId);
+        return;
+    }
     auto& hwcInfo = getBE().mHwcLayers[displayId];
     auto& hwcLayer = hwcInfo.layer;
     auto error = hwcLayer->setVisibleRegion(visible);

services/surfaceflinger/Layer.cpp

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index e17589f..5a0bf43 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -482,6 +482,11 @@
 
 void Layer::setGeometry(const sp<const DisplayDevice>& display, uint32_t z) {
     const auto displayId = display->getId();
+    if (!hasHwcLayer(displayId)) {
+        ALOGE("[%s] failed to setGeometry: no HWC layer found (%d)",
+              mName.string(), displayId);
+        return;
+    }
     auto& hwcInfo = getBE().mHwcLayers[displayId];
 
     // enable this layer
@@ -1980,6 +1985,10 @@
 }
 
 void Layer::writeToProto(LayerProto* layerInfo, int32_t displayId) {
+    if (!hasHwcLayer(displayId)) {
+        return;
+    }
+
     writeToProto(layerInfo, LayerVector::StateSet::Drawing);
 
     const auto& hwcInfo = getBE().mHwcLayers.at(displayId);