Opterons and the NX flag.

[Patrick Flaherty <patrick@activmedia.com>]

According to the 2.6.8 change log, Ingo added support to boot smp
opterons in NX mode. Which is fantastic as NX adds a modicom of buffer
overflow protection. What I've never understood is how to enable NX
pages. There dosn't seem to be a kernel option for it, is it on by
default? Has anyone been using it on their system? Does it break any
programs (apparently some jit compilers use data pages as executables)?

Thanks,
patrick

p.s. NX stands for no exec or somthing, and has been on high end
processors for a long time. basicaly pages in memory marked by the nx
flag can't be used to store any shell code (what does bad things in
buffer overflows)