In article <20070712202114.GY986@snowdrop.l8s.co.uk>,
David Laight  <david@l8s.co.uk> wrote:
>After much hacking, there is now only one piece of code that relies on the
>'stackgap' [1], this isn't in the compat code, but is in kern/krn_systrace.c.
>
>Anyone any thoughts on how to implement the systrace STRIOCREPLACE ioctl?
>Or is systrace just such a nasty hack it deserves to die?

I don't see how to, without changing a lot of other code. I think
that the current implementation of systrace is problematic in
threaded programs threads can interfere and change arguments of
syscalls after systrace have validated them but before the kernel
has executed them.

christos