commit f9096655b6c0dc377786553486a11c0197ab91ea
author Vishnu Nair <vishnun@google.com> Tue Jul 20 18:49:42 2021 -0700
committer Vishnu Nair <vishnun@google.com> Wed Jul 21 02:17:28 2021 +0000
tree 47f7194f9a59f87bc9b034c944b81cedcbdc5654
parent ce4973ba674adfa7d3baaed49edcb8bac9cc8c40

SurfaceFlinger: Safely cast from IBinder to Layer::Handle

Bug: b/193034677, b/193034683, b/193033243
Test: go/wm-smoke, presubmit

Change-Id: Iece64fca254edfd0b82e05ad9629824b2364cc13

services/surfaceflinger/SurfaceInterceptor.cpp

diff --git a/services/surfaceflinger/SurfaceInterceptor.cpp b/services/surfaceflinger/SurfaceInterceptor.cpp
index 2084bb6..6f1a0f6 100644
--- a/services/surfaceflinger/SurfaceInterceptor.cpp
+++ b/services/surfaceflinger/SurfaceInterceptor.cpp
@@ -183,12 +183,9 @@
     return NO_ERROR;
 }
 
-const sp<const Layer> SurfaceInterceptor::getLayer(const wp<const IBinder>& weakHandle) const {
-    const sp<const IBinder>& handle(weakHandle.promote());
-    const auto layerHandle(static_cast<const Layer::Handle*>(handle.get()));
-    const sp<const Layer> layer(layerHandle->owner.promote());
-    // layer could be a nullptr at this point
-    return layer;
+const sp<const Layer> SurfaceInterceptor::getLayer(const wp<IBinder>& weakHandle) const {
+    sp<IBinder> handle = weakHandle.promote();
+    return Layer::fromHandle(handle).promote();
 }
 
 int32_t SurfaceInterceptor::getLayerId(const sp<const Layer>& layer) const {
@@ -203,12 +200,11 @@
     return strongLayer == nullptr ? -1 : getLayerId(strongLayer);
 }
 
-int32_t SurfaceInterceptor::getLayerIdFromHandle(const sp<const IBinder>& handle) const {
+int32_t SurfaceInterceptor::getLayerIdFromHandle(const sp<IBinder>& handle) const {
     if (handle == nullptr) {
         return -1;
     }
-    const auto layerHandle(static_cast<const Layer::Handle*>(handle.get()));
-    const sp<const Layer> layer(layerHandle->owner.promote());
+    const sp<const Layer> layer = Layer::fromHandle(handle).promote();
     return layer == nullptr ? -1 : getLayerId(layer);
 }