Fix: avoid dereferencing future flatBuffer address

shahor02 · shahor02 · commit 2d7869cfd128 · 2019-05-20T13:42:36.000+02:00
diff --git a/Detectors/Base/include/DetectorsBase/MatLayerCylSet.h b/Detectors/Base/include/DetectorsBase/MatLayerCylSet.h
@@ -104,7 +104,7 @@ class MatLayerCylSet : public o2::gpu::FlatObject
   using o2::gpu::FlatObject::releaseInternalBuffer;
 
   void fixPointers(char* newPtr = nullptr);
-  void fixPointers(char* oldPtr, char* newPtr);
+  void fixPointers(char* oldPtr, char* newPtr, bool newPtrValid = true);
 
   /// Gives minimal alignment in bytes required for the class object
   static constexpr size_t getClassAlignmentBytes() { return 8; }
diff --git a/Detectors/Base/src/MatLayerCylSet.cxx b/Detectors/Base/src/MatLayerCylSet.cxx
@@ -449,7 +449,7 @@ void MatLayerCylSet::setFutureBufferAddress(char* futureFlatBufferPtr)
 {
   /// Sets the actual location of the external flat buffer before it was created
   ///
-  fixPointers(mFlatBufferPtr, futureFlatBufferPtr);
+  fixPointers(mFlatBufferPtr, futureFlatBufferPtr, false); // flag that futureFlatBufferPtr is not valid yet
   flatObject::setFutureBufferAddress(futureFlatBufferPtr);
 }
 
@@ -484,16 +484,19 @@ void MatLayerCylSet::fixPointers(char* newBasePtr)
 }
 
 //______________________________________________
-void MatLayerCylSet::fixPointers(char* oldPtr, char* newPtr)
+void MatLayerCylSet::fixPointers(char* oldPtr, char* newPtr, bool newPtrValid)
 {
   // fix pointers on the internal structure of the flat buffer after retrieving it from the file
+  auto* layPtr = get()->mLayers;
   get()->mLayers = flatObject::relocatePointer(oldPtr, newPtr, get()->mLayers);
   get()->mR2Intervals = flatObject::relocatePointer(oldPtr, newPtr, get()->mR2Intervals);
   get()->mInterval2LrID = flatObject::relocatePointer(oldPtr, newPtr, get()->mInterval2LrID);
-
+  if (newPtrValid) {
+    layPtr = get()->mLayers;
+  }
   for (int i = 0; i < getNLayers(); i++) {
-    get()->mLayers[i].setFlatPointer(flatObject::relocatePointer(oldPtr, newPtr, get()->mLayers[i].getFlatBufferPtr()));
-    get()->mLayers[i].fixPointers(oldPtr, newPtr);
+    layPtr[i].setFlatPointer(flatObject::relocatePointer(oldPtr, newPtr, layPtr[i].getFlatBufferPtr()));
+    layPtr[i].fixPointers(oldPtr, newPtr);
   }
 }
 #endif // !GPUCA_GPUCODE

Original file line number	Diff line number	Diff line change
`@@ -449,7 +449,7 @@ void MatLayerCylSet::setFutureBufferAddress(char* futureFlatBufferPtr)`
`449`	`449`	`{`
`450`	`450`	`/// Sets the actual location of the external flat buffer before it was created`
`451`	`451`	`///`
`452`		`- fixPointers(mFlatBufferPtr, futureFlatBufferPtr);`
	`452`	`+ fixPointers(mFlatBufferPtr, futureFlatBufferPtr, false); // flag that futureFlatBufferPtr is not valid yet`
`453`	`453`	`flatObject::setFutureBufferAddress(futureFlatBufferPtr);`
`454`	`454`	`}`
`455`	`455`
`@@ -484,16 +484,19 @@ void MatLayerCylSet::fixPointers(char* newBasePtr)`
`484`	`484`	`}`
`485`	`485`
`486`	`486`	`//______________________________________________`
`487`		`-void MatLayerCylSet::fixPointers(char* oldPtr, char* newPtr)`
	`487`	`+void MatLayerCylSet::fixPointers(char* oldPtr, char* newPtr, bool newPtrValid)`
`488`	`488`	`{`
`489`	`489`	`// fix pointers on the internal structure of the flat buffer after retrieving it from the file`
	`490`	`+ auto* layPtr = get()->mLayers;`
`490`	`491`	`get()->mLayers = flatObject::relocatePointer(oldPtr, newPtr, get()->mLayers);`
`491`	`492`	`get()->mR2Intervals = flatObject::relocatePointer(oldPtr, newPtr, get()->mR2Intervals);`
`492`	`493`	`get()->mInterval2LrID = flatObject::relocatePointer(oldPtr, newPtr, get()->mInterval2LrID);`
`493`		`-`
	`494`	`+ if (newPtrValid) {`
	`495`	`+ layPtr = get()->mLayers;`
	`496`	`+ }`
`494`	`497`	`for (int i = 0; i < getNLayers(); i++) {`
`495`		`- get()->mLayers[i].setFlatPointer(flatObject::relocatePointer(oldPtr, newPtr, get()->mLayers[i].getFlatBufferPtr()));`
`496`		`- get()->mLayers[i].fixPointers(oldPtr, newPtr);`
	`498`	`+ layPtr[i].setFlatPointer(flatObject::relocatePointer(oldPtr, newPtr, layPtr[i].getFlatBufferPtr()));`
	`499`	`+ layPtr[i].fixPointers(oldPtr, newPtr);`
`497`	`500`	`}`
`498`	`501`	`}`
`499`	`502`	`#endif // !GPUCA_GPUCODE`