Re: [PATCH bpf-next v1 00/13] MAC and Audit policy using eBPF (KRSI)

[Greg Kroah-Hartman]

On Fri, Jan 10, 2020 at 05:11:38AM +1100, James Morris wrote:
> On Wed, 8 Jan 2020, Stephen Smalley wrote:
> 
> > The cover letter subject line and the Kconfig help text refer to it as a
> > BPF-based "MAC and Audit policy".  It has an enforce config option that
> > enables the bpf programs to deny access, providing access control. IIRC, in
> > the earlier discussion threads, the BPF maintainers suggested that Smack and
> > other LSMs could be entirely re-implemented via it in the future, and that
> > such an implementation would be more optimal.
> 
> In this case, the eBPF code is similar to a kernel module, rather than a 
> loadable policy file.  It's a loadable mechanism, rather than a policy, in 
> my view.
> 
> This would be similar to the difference between iptables rules and 
> loadable eBPF networking code.  I'd be interested to know how the 
> eBPF networking scenarios are handled wrt kernel ABI.

I already know of some people who pre-compile ebpf programs based on a
number of "supported" kernel versions and then load the needed one at
runtime.

Messy, yes, but you are right, ebpf code is much more similiar to a
kernel module than userspace code at the moment.

thanks,

greg k-h