Re: [PATCH v25 10/12] LRNG - add TRNG support

From: Greg Kroah-Hartman
Date: Wed Nov 20 2019 - 08:29:24 EST


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