* Ram Pai:

Testing:
-------
This patch series has passed all the protection key
tests available in the selftest directory.The
tests are updated to work on both x86 and powerpc.
The selftests have passed on x86 and powerpc hardware.

How do you deal with the key reuse problem?  Is it the same as x86-64,
where it's quite easy to accidentally grant existing threads access to
a just-allocated key, either due to key reuse or a changed init_pkru
parameter?

What about siglongjmp from a signal handler?

  <https://sourceware.org/bugzilla/show_bug.cgi?id=22396>

I wonder if it's possible to fix some of these things before the exact
semantics of these interfaces are set in stone.