Ryzen issues on FreeBSD ? (with sort of workaround)

[Pete French]

> I just brought everything upto date and re-tested and same issue.
> FreeBSD 11.2-STABLE #1 r336761
> 
> # mount | grep -v zfs
> devfs on /dev (devfs, local, multilabel)
> linprocfs on /compat/linux/proc (linprocfs, local)
> linsysfs on /compat/linux/sys (linsysfs, local)
> tmpfs on /compat/linux/dev/shm (tmpfs, local)
> 
> # /compat/linux/bin/bash
> Segmentation fault (core dumped)
> #
> 

I opened a bug report for this here:

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230144

It definitely processor dependent (booting same drive on two different 
CPUs shows it up) and it does not happen on CURRENT. Very odd indeed!

-pete.