Shouldn't be applied without Roland's ack.
I just don't know how to merge the second patch properly. I think it would be
really nice to cleanup ptrace attach before ptracee data structures cleanup,
but this depends on utrace-core.patch which adds exclude_ptrace().
With the first patch, the
Remove the Nasty, nasty lock dance in ptrace_attach()/ptrace_traceme().
From now task_lock() has nothing to do with ptrace at all.
With the recent changes nobody uses task_lock() to serialize with ptrace,
but in fact it was never needed and it was never used consistently.
However ptrace_attach()
