CS161 2019-02-14
Zhu, Justin

CS161 2019-02-14
Thu, Feb 14, 2019

Side channels in the microarchitecture. Google Project Zero finds security vulnerabilities, report these vulnerabilities in a responsible fashion.

We can have a better OS.

Race condition, fetch memory stores in cache and then accesses it from later processes.

Virtual memory is defined by PT, PTP, PTW, and PTEU. If PTEU is not set, user process cannot access that page. If user access tries to access a page, then page fault happens.

The kernel then takes control.

What’s wrong?

The kernel might have done some other things.

These instructions don’t exist in the hardware and then get coded in microops. Move 2 off from rax into rbx. Decode and then it goes to the reorder buffer. We have wires that reschedule things where CPU reorders everything that it like.

Then we shove it into the execution units and everything’s good