Through Computer Architecture, Darkly

Spectre,¹¹ Meltdown,¹³ Foreshadow,^18,20 Rowhammer,⁹ Spoiler,⁹—suddenly it seems as if there is a new and unending stream of vulnerabilities in processors. Previous niche concepts such as speculative execution and cache timing side-channels have taken center stage. Across the whole hardware/software system, new vulnerabilities such as insufficiently protected memory access from untrustworthy PCIe or Thunderbolt USB-C peripherals,¹⁵ malicious Wi-Fi firmware,⁴ or alleged hardware implants¹⁴ are also starting to emerge.

We may be facing a crisis in systems design. What might we do about it? Here, we consider whether existing approaches are adequate, and where substantial new work is needed.