PE Loader Questions

[dila]

Hello, I have a number of questions about the PE file format, and what is considered a valid/loadable file by the OS.

Here's a few of my thoughts while coding a PE loader:

1) Is it possible that a valid executable can have overlapping sections?
2) Is it possible for a single code instruction to overflow into another section?
3) Is it possible to have executable code between two sections, and if so, what memory characteristics are given to data in such a region?

Regards!