Q: When I compile the kernel with the patch I get an error like:
ip_output.c:xxx:parse error before '@'
A: You have not done a make patches as it says in the installation section of the web page.
Q: How do I patch the kernel if I have 2.x.x instead of 2.2.3?
A: You go into the patches directory
of the useripacct package, and copy the relevant patch from one of the
sub-directories to this directory. You, then edit the Makefile and
change the PATCHES= line to the relecant patch name, and you run make patches
from the main useripacct directory.