svn commit: r257696 - in head: libexec/rbootd share/man/man9 sys/compat/svr4 sys/net sys/sys

[Peter Wemm]

On Tue, Nov 5, 2013 at 11:29 AM, Gleb Smirnoff <glebius at freebsd.org> wrote:

> On Tue, Nov 05, 2013 at 11:56:09AM -0500, John Baldwin wrote:
> J> On Tuesday, November 05, 2013 5:29:48 am Gleb Smirnoff wrote:
> J> > Author: glebius
> J> > Date: Tue Nov  5 10:29:47 2013
> J> > New Revision: 257696
> J> > URL: http://svnweb.freebsd.org/changeset/base/257696
> J> >
> J> > Log:
> J> >   Drop support for historic ioctls and also undefine them, so that
> code
> J> >   that checks their presence via ifdef, won't use them.
> J>
> J> Most of these are COMPAT_43, but one appears to be a 9.x ioctl?  If
> that's the
> J> case it's implementation should probably stick around under appropriate
> J> COMPAT_FREEBSD<x> macros.  It looks like it goes all the way back to
> 4.4BSD,
> J> so at least COMPAT_FREEBSD4 and later should define the implementation
> to
> J> preserve ABI compat for old binaries.
>
> Why should we support such broken configurations as running new kernel and
> ancient core base system utilities? The efforts to keep this are much more
> expensive, then yields.
>
>
Why? because up until now you could run a FreeBSD4 jail on a modern system
and reasonably expect it to work.  No, we don't really "support" system
level tools, but examining network state is widely used.  No, one doesn't
run ifconfig to set interface configs in jails, but there's a lot of
scripts to read the configuration.


> The only reason I see is to keep compat for the previous major version,
> since
> we guarantee only consequtive upgrades to a next major. If something goes
> wrong during upgrade a sysadmin can use old tools with new kernel. I agree
> on
> that, and when changing SIOCAIFADDR two years ago, I provided
> compatibility.
>
> But why the hell should we support an insane who will try to run
> ifconfig(8)
> from FreeBSD 4 on FreeBSD 11? Not speaking about this tool from 4.4BSD,
> LOL :)
> This is not what COMPAT_FREEBSD4 meant to be.
>

Insane? Perhaps, but it's keeping FreeBSD alive in a fairly large company I
know of.  We'll have to locally revert this change, most likely, and spend
time supporting it ourselves instead of doing other potentially more useful
things to help FreeBSD in general.

-- 
Peter Wemm - peter at wemm.org; peter at FreeBSD.org; peter at yahoo-inc.com; KI6FJV