The Raspberry Pi, the little single-board computer that is used by enthusiasts, is not vulnerable to either the Meltdown bug that was revealed this week to be affecting most Intel processors made since 1995, the founder of the Raspberry Pi project says.
Eben Upton said the Raspberry Pi was also not vulnerable to the Spectre bug which, apart from all Intel processors, also affects some ARM and AMD chips.
In a detailed post, Upton said both vulnerabilities exploited performance features — caching and speculative execution — common to many modern processors to leak data via a so-called side-channel attack.
"Happily, the Raspberry Pi isn’t susceptible to these vulnerabilities, because of the particular ARM cores that we use," he added.
{loadposition sam08}Upton outlined some concepts in modern processor design in great detail to explain his point.
He said modern processors went to great lengths "to preserve the abstraction that they are in-order scalar machines that access memory directly, while in fact using a host of techniques including caching, instruction reordering, and speculation to deliver much higher performance than a simple processor could hope to achieve".
"Meltdown and Spectre are examples of what happens when we reason about security in the context of that abstraction, and then encounter minor discrepancies between the abstraction and reality," he said.
The lack of speculation in the ARM1176, Cortex-A7, and Cortex-A53 cores used in Raspberry Pi render the board immune to attacks of the sort.