From mboxrd@z Thu Jan  1 00:00:00 1970
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH v25 10/12] LRNG - add TRNG support
Date: Wed, 20 Nov 2019 14:29:18 +0100
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Cc: Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>, Linux Crypto Mailing List <linux-crypto@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>, Linux API <linux-api@vger.kernel.org>, "Eric W. Biederman" <ebiederm@xmission.com>, "Alexander E. Patrakov" <patrakov@gmail.com>, "Ahmed S. Darwish" <darwish.07@gmail.com>, "Theodore Y. Ts'o" <tytso@mit.edu>, Willy Tarreau <w@1wt.eu>, Matthew Garrett <mjg59@srcf.ucam.org>, Vito Caputo <vcaputo@pengaru.com>, Andreas Dilger <adilger.kernel@dilger.ca>, Jan Kara <jack@suse.cz>, Ray Strode <rstrode@redhat.com>, William Jon McCann <mccann@jhu.edu>, zhangjs <zachary@baishancloud.com>, Florian Weimer <fweimer@redhat.com>, Lennart Poettering <mzxreary@0pointer.de>, Nicolai Stange <nstange@suse.de>P
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On Wed, Nov 20, 2019 at 09:58:35AM +0100, Stephan Müller wrote:
> Am Dienstag, 19. November 2019, 13:41:50 CET schrieb Greg Kroah-Hartman:
> 
> Hi Greg,
> 
> > On Tue, Nov 19, 2019 at 02:07:40AM -0800, Andy Lutomirski wrote:
> > > > As this would introduce a new device file now, is there a special
> > > > process that I need to follow or do I need to copy? Which major/minor
> > > > number should I use?
> > > > 
> > > > Looking into static const struct memdev devlist[] I see
> > > > 
> > > >          [8] = { "random", 0666, &random_fops, 0 },
> > > >          [9] = { "urandom", 0666, &urandom_fops, 0 },
> > > > 
> > > > Shall a true_random be added here with [10]?
> > > 
> > > I am not at all an expert on chardevs, but this sounds generally
> > > reasonable.  gregkh is probably the real authority here.
> > 
> > [10] is the aio char device node, so you better not try to overlap it or
> > bad things will happen :(
> 
> Thanks for your insights.
> 
> Which device minor number could we use?

Get your own dynamic one by using a misc device if you _REALLY_ want to
add yet-another-char-node-for-random-data.

But I would have thought that we all realize that this is not the way to
do things.  Let's not have "random", "urandom", and "true_random" be
something we want to totally confuse userspace with, that way is insane.

Please just make the existing userspace api "just work", don't add to
the mess.

thanks,

greg k-h