armcpu-cachecortex-aspectre

Cortex-A8 out-of-order execution and Spectre

I am reading about ARM Cortex-A8 processor and found that this processor does not support out-of-order execution. However, in https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability Arm clarified that Cortex-A8 is vulnerable against Spectre-v1 and Spectre-v2 attack.

I wonder how Spectre attack can be implemented without Out Of Order execution. Can anyone help me to find reason of that?

Solution

  • An in-order processor can speculate ahead of the current point of execution; you don't need a full out-of-order design for Spectre to be a problem.