Re: random.c backports for 5.18, 5.17, 5.15, and prior

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Jun 10, 2022 at 11:05:56AM +0200, Jason A. Donenfeld wrote:
> Hi Greg,
> 
> On Mon, May 30, 2022 at 12:38:15PM +0200, Jason A. Donenfeld wrote:
> > Hey Greg,
> > 
> > I think if it's in 5.10, it makes sense to at least try to get it into
> > 5.4 and below for the same reasons. I'm traveling over the next week or
> > so, but I think I'll attempt to do a straight backport of it (sans-wg)
> > like I did for 5.10. As mentioned, it's harder, but that doesn't mean
> > it's impossible. I might give up in exasperation or perhaps find it too
> > onerous. But hopefully I'll be able to reuse the work I did for the
> > Android wg backports. Anyway, no guarantees -- it's not a trivial walk
> > in the park -- but I'll give it a shot and let you know if I can make it
> > work.
> 
> I'm glad I tried, because that turned out to be really easy, and none of
> the concerns I had about the crypto turned out to be valid at all. A lot
> of the hairiness with the 5.6-era crypto code was the way that
> lib/crypto/ interacted with kconfig and crypto/, and the way arch crypto
> interacted with that. But for blake2s, there was just a single commit to
> backport, which didn't need to interact with anything else, because
> there was nothing prior in the kernel regarding blake2s. So it wound up
> just being a boring lib/ commit, with no complications.
> 
> So with that out of the way, I succeeded in doing the remaining
> backports. You can pull from
> https://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git/ the
> following branches, with a linear series of commits on top of your
> latest:
> 
>     - linux-4.9.y
>     - linux-4.14.y
>     - linux-4.19.y
>     - linux-5.4.y
> 
> I've done an `allmodconfig` build test on these, and I've also booted a
> system on each of them. They contain the fixes that have landed since
> the previous tranche of backports, so that should bring all the
> backports up to date with each other.
> 
> And that means that moving forward, a `Cc: stable@vger.kernel.org` tag
> will hopefully apply evenly and without hassle to everything. More
> globally, I noticed when doing these backports what had been already
> backported and what hadn't, and it looks like a lot didn't easily apply
> before and so was dropped without being reworked, so over time fixes
> were lost. So I'm very happy to bring everything up to date finally.

All now queued up, thanks.

greg k-h