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.
