Subroutine Purpose Maps a file-system object into virtual memory. Unexpected results may occur when references are made beyond the end of the object.
Care needs to be taken when using the mmap subroutine if the program attempts to map itself.
If the page containing executing instructions is currently referenced as data through an mmap mapping, the program will hang. Use the -H4096 binder option, and that will put the executable text on page boundries. Then reset the file that contains the executable material, and view via an mmap mapping. A region created by the mmap subroutine cannot be used as the buffer for read or write operations that involve a device. Similarly, an mmap region cannot be used as the buffer for operations that require either a pin or xmattach operation on the buffer.