[ros-kernel] Registry issues

[Eric Kohl]

Hi everyone!

I got a bug report about a corrupted registry a few days ago. I analyzed the
included system hive and found out that a hive file can be damaged in
_very_rare_ cases. That's why I did not report it as a showstopper. The main
cause of the bug is that a key-cell is modified when a subkey is added but
the key-cell's block is not marked dirty if the all the other involved
structures are located in other blocks. This causes a dangling-pointer bug
if the subkey-list-cell (aka hash-cell) grows and moves to a new location.

One major weakness of the NT4-compatible implementation is that two
structures, value list cells and value data cells, do not have an id or
magic value to verify their identity. My plan is to add the missing id
values and implement a test upon load/import in order to verify the
integrity of the hive.

Any comments?


Eric