cvs commit: src/sys/amd64/amd64 mp_machdep.csrc/sys/amd64/include cpufunc.h src/sys/i386/i386 mp_machdep.c src/sys/i386/include cpufunc.h

[Colin Percival]

Nate Lawson wrote:
> Every general-purpose machine has measurable timing side channels.  The
> question is merely one of bandwidth.

Absolutely.  Most covert channels operate at up to a few kbps; this covert
channel operates at several Mbps.

The fact that this channel is many times faster than all the other channels
combined makes it not just quantitatively different but also qualitatively
different and deserving of more careful treatment.

Colin Percival