"BUG: scheduling while atomic" on 5.4 kernels with PREEMPT_RT

[Jason A. Donenfeld]

Hi Erik,

So far as I can tell, upstream is fine with this. I'd encourage you to
move to the newer LTS, 5.10. The compat stuff has always been pretty
meh. It was an important step in getting WireGuard bootstrapped, of
course, but just look at this horror:

https://git.zx2c4.com/wireguard-linux-compat/tree/src/compat/compat.h

I'll keep it working as people need, but folks should really really
move to the new LTS, now that it's out.

I've also backported upstream commit-by-commit to 5.4 (and android
4.19), for stable kernels, as used by Oracle, SUSE, Google, and so on:
https://git.zx2c4.com/wireguard-linux/log/?h=backport-5.4.y
This too is much preferable to using the compat stuff.

Jason