Subject: Re: @booted_kernel magic symlink?
To: Chapman Flack <nblists@anastigmatix.net>
From: Garrett D'Amore <garrett_damore@tadpole.com>
List: tech-kern
Date: 04/26/2006 20:45:42
Chapman Flack wrote:
> Garrett D'Amore wrote:
>> If I had a little more time, I'd go ahead and try to fix the kernel
>> grovelers myself.  I don't know how many of them are out there, but
>> there aren't many.
>
> egrep -rl '(getbootfile|kvm_openfiles)' /usr/src/*bin  turns up:
>
> sbin/savecore
> sbin/ccdconfig
> usr.bin/fstat
> usr.bin/ipcs
> usr.bin/netstat
> usr.bin/nfsstat
> usr.bin/pkill
> usr.bin/pmap
> usr.bin/systat
> usr.bin/vmstat
> usr.bin/w
> usr.sbin/ifmcstat
> usr.sbin/kgmon
> usr.sbin/mlxctl
> usr.sbin/ntp
> usr.sbin/pstat
> usr.sbin/trpt
> usr.sbin/trsp
>
> If there are any grovelers that don't actually use getbootfile
> or kvm_openfiles, they'll be in addition to the list above.

There are those above that are not necessarily grovelers as well.  I.e.
some of them may fall back to groveling with sysctl fails.

Its surprising to me that pkill and w are in that list.

    -- Garrett
>
>> From experience, netstat usually misbehaves silently if it is looking
> at the wrong kernel, say by giving reasonable-looking but incomplete
> lists of listening sockets for -a. In netstat's case I confirmed that
> was the problem (and not, say, that I'd been rooted by some stealthy
> bugger) by getting the correct results after specifying the correct
> kernel.  I haven't systematically checked to see how all the others
> behave; of course one would prefer to get an error or obvious nonsense,
> but that seems very rarely to be what really happens.  (I first noticed
> the trouble with savecore when it was saying wd0a wasn't readable,
> which concerned me until I remembered that machine hasn't got a wd0a,
> and then concerned me a different way).
>
> My feeling's that a system known to ship with at least 18 kvm grovellers
> ought also to ship with a simple, prominently documented workaround
> for use cases where the grovellers would otherwise show heisenbehavior,
> and that it should ship that way for as long as it takes for sysctl to
> be extended with all of the internal interfaces needed by the >= 18
> grovellers, and for them to be rewritten to use it.
>
> -Chap


-- 
Garrett D'Amore, Principal Software Engineer
Tadpole Computer / Computing Technologies Division,
General Dynamics C4 Systems
http://www.tadpolecomputer.com/
Phone: 951 325-2134  Fax: 951 325-2191