linux-oracle-jre18-8.221 in jail as non-root user

[Greg Lewis]

On Fri, Aug 23, 2019 at 05:43:22AM +0000, Miroslav Šilhavý wrote:
> Hello,
> I am trying to get linux-oracle-jre18-8.221 working within a jail as non privileged user.
> 
> When I install the package (from ports) on raw FBSD 12, everything works OK. Java is able to run under root account and under arbitrary user as well.
> 
> When I reproduce the same steps within a jail, I am able to run java under root account. But under arbitrary user java binary gets stucked. I am trying to run pure java binary (/usr/local/linux-oracle-jre1.8.0/bin/java) with no parameters which should lead to print java’s usage help. But execution stucks, nothing is printed to output and binary never finishes.
> 
> Is it even possible to run Oracle Java under jail under unprivileged user? Do I miss something?

The Linux JDKs rely at least to some extent on access to Linux's /proc
filesystem.  Is /compat/linux/proc visible inside of the jail?  If not
that might be something to look at.

-- Greg