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Date:   Wed, 11 May 2022 00:50:11 +0200
From:   "Jason A. Donenfeld" <Jason@zx2c4.com>
To:     Simo Sorce <simo@redhat.com>
Cc:     dodis@cs.nyu.edu, tytso@mit.edu, nadiah@cs.ucsd.edu,
        noahsd@gmail.com, tessaro@cs.washington.edu,
        torvalds@linux-foundation.org, jeanphilippe.aumasson@gmail.com,
        jann@thejh.net, keescook@chromium.org, gregkh@linuxfoundation.org,
        peter@cryptojedi.org, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org, "D. J. Bernstein" <djb@cr.yp.to>
Subject: Re: is "premature next" a real world rng concern, or just an
 academic exercise?
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Hi Simo,

On Tue, May 10, 2022 at 05:33:34PM -0400, Simo Sorce wrote:
> On Tue, 2022-05-10 at 22:09 +0200, Jason A. Donenfeld wrote:
> > For 5.19 (or at this point, more likely 5.20), there's a userspace
> > notifier in store, maybe, if I can figure out how to do it right.
> > There's a pretty bikesheddy thread here on what shape that interface
> > should take: https://lore.kernel.org/lkml/YnA5CUJKvqmXJxf2@zx2c4.com/
> > But basically there are some details about how an async interface should
> > work, and what the virtual hardware future, if any, looks like for a
> > memory mapped race-free polling interface. Plus some considerations on
> > how much we should care etc.
> 
> Perhaps it might be simpler to add an "epoch" number or similar exposed
> [...]

Could you send these ideas to the bikeshed thread that I linked rather
than this premature next one. I think it'd be a good idea to keep Alex
and Lennart looped in to that discussion, since they represent userspace
projects that probably care about it, and not bog this one down with
systems programming things pretty far from premature next threat model
stuff. It's a bikeshed thing, after all...

Thanks,
Jason