Re: Linux 5.3-rc8

[Jon Masters]

On 9/10/19 12:21 AM, Ahmed S. Darwish wrote:

> Can this even be considered a user-space breakage? I'm honestly not
> sure. On my modern RDRAND-capable x86, just running rng-tools rngd(8)
> early-on fixes the problem. I'm not sure about the status of older
> CPUs though.

Tangent: I asked aloud on Twitter last night if anyone had exploited
Rowhammer-like effects to generate entropy...and sure enough, the usual
suspects have: https://arxiv.org/pdf/1808.04286.pdf

While this requires low level access to a memory controller, it's
perhaps an example of something a platform designer could look at as a
source to introduce boot-time entropy for e.g. EFI_RNG_PROTOCOL even on
an existing platform without dedicated hardware for the purpose.

Just a thought.

Jon.