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@xxxxxxxxxxxxxxx` 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. Regards, Jason
