Re: end of x86 & x64?
the performance penalty inherent to context switching
One thing we've learned over the last week is that speeding things up at the cost of security is not a great idea. And it's a bit of a circular argument in any case - the faster mode switch, SYSCALL, only provides a kernel mode switch as the other modes weren't actually being used. We really need to look at what we need in terms of security, not constantly optimise and compromise for benchmarks.
And we need to do it right. As I've been delving into this a bit deeper, I notice that AMD's encrypted memory does notseem to extend past the memory bus - information in the cache (and CPU) is in the clear. That means similar side-channel techniques could potentially be used to bypass memory encryption. It's going to take some time to get our collective heads around this.
Biting the hand that feeds IT
