The thing is, this can be disabled A) per thread, and B) can't leak from other processes (it's flushed on each context switch). So really, we want certain proc

The thing is, this can be disabled A) per thread, and B) can't leak from other processes (it's flushed on each context switch). So really, we want certain processes with software based sandboxing -- e.g. Javascript interpreters-- to turn this off.