September 2007 - Posts

• MSIL Verification Notes - 4

  I thought I knew what is box and unbox. After reading the ECMA spec, I know that what I believed was actually wrong. Maybe you had the same incorrect impression in your mind. Box a integer will create an object on the heap and copy the date from valuetype Read More... Posted Wednesday, September 26, 2007 2:19 PM by ZifengH | 0 Comments

• MSIL Verification Notes - 3

  Below code tries to return a ByRef object which points on a stack location. CLR rule considers this kind of ByRef object is not safe to return to the caller. .method public instance int32& modopt([Microsoft.VisualC]Microsoft.VisualC.IsCXXPointerModifier) Read More... Posted Tuesday, September 25, 2007 7:23 PM by ZifengH | 1 Comments

• MSIL Verification Notes - 2

  MSIL (or CIL) uses a stack based model. To make sure that Type-safe code to be secure, it can only access the meory locations it is authorized to acess. We verify the type on the stack. If the data type on the stack does not match the expection of an Read More... Posted Monday, September 24, 2007 6:38 PM by ZifengH | 1 Comments

• MSIL Verification Notes - 1

  I am recently working on some IL verification related scenario. IL verification is critical for CLR security. As CLR support for Silverlight approaching, it is a critical to make sure that our JIT can verify IL code correctly. I figured it would be interesting Read More... Posted Friday, September 21, 2007 2:30 PM by ZifengH | 1 Comments