Now, if the trap occurs on every access, you have a lot of overhead that
should be bench-marked so that users can make security decisions based
upon knowledge rather than emotion.
If the trap occurs only when the code-segment is changed within the
user environment, you haven't fixed anything because the stack may
be reachable within the current code-segment, although not at the
current offset.
If the trap occurs by marking pages not present and having the page-fault
handler confirm/deny access, you have the problem of granularity. A
lot of rogue code can fit within a page.
So, just how does this new code work? Or is it a feature for the Suns
only?
Cheers,
Dick Johnson
Penguin : Linux version 2.3.13 on an i686 machine (400.59 BogoMips).
Warning : The end of the world as we know it requires a new calendar.
Seconds : 307604 (until Y2K)
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