Re: [PATCH v36 00/13] /dev/random - a new approach

From: Greg Kroah-Hartman
Date: Wed Oct 28 2020 - 17:42:39 EST


On Wed, Oct 28, 2020 at 06:51:17PM +0100, Torsten Duwe wrote:
> On Mon, 19 Oct 2020 21:28:50 +0200
> Stephan Müller <smueller@xxxxxxxxxx> wrote:
> [...]
> > * Sole use of crypto for data processing:
> [...]
> > - The LRNG uses only properly defined and implemented cryptographic
> > algorithms unlike the use of the SHA-1 transformation in the
> > existing /dev/random implementation.
> >
> > - Hash operations use NUMA-node-local hash instances to benefit large
> > parallel systems.
> >
> > - LRNG uses limited number of data post-processing steps
> [...]
> > * Performance
> >
> > - Faster by up to 75% in the critical code path of the interrupt
> > handler depending on data collection size configurable at kernel
> > compile time - the default is about equal in performance with
> > existing /dev/random as outlined in [2] section 4.2.
>
> [...]
> > - ChaCha20 DRNG is significantly faster as implemented in the
> > existing /dev/random as demonstrated with [2] table 2.
> >
> > - Faster entropy collection during boot time to reach fully seeded
> > level, including on virtual systems or systems with SSDs as
> > outlined in [2] section 4.1.
> >
> > * Testing
> [...]
>
> So we now have 2 proposals for a state-of-the-art RNG, and over a month
> without a single comment on-topic from any `get_maintainer.pl`
>
> I don't want to emphasise the certification aspects so much. The
> interrelation is rather that those certifications require certain code
> features, features which are reasonable per se. But the current code is
> lagging way behind.
>
> I see the focus namely on performance, scalability, testability and
> virtualisation. And it certainly is an advantage to use the code
> already present under crypto, with its optimisations, and not rely
> on some home brew.
>
> Can we please have a discussion about how to proceed?
> Ted, Greg, Arnd: which approach would you prefer?

Greg and Arnd are not the random driver maintainers, as is now correctly
shown in the 5.10-rc1 MAINTAINERS file, so I doubt we (well at least I)
have any say here, sorry.

good luck!

greg k-h