stable/9 @r241776 panic: REDZONE: Buffer underflow detected...

[David Wolfskill]

On Sun, Oct 21, 2012 at 03:13:56PM +0300, Konstantin Belousov wrote:
> ...
> > Anyone else seeing this?  Any ideas how to diagnose it?
> 
> devread is the method of devctl(4) which passes devd notifications from
> the kernel to userland (to devd, specifically). There were no changes to
> devctl(4) for quite a time.

I noticed that none of the changes in the last update seemed at all
relevant, yes.  And thank you for the background (devread()).

> The corruption is, most likely, in some unrelated piece of code. Could
> you try to bisect the stable to catch the offender ? The bisect is not
> guaranteed to work, obviously, since the random corruption effects are
> unpredictable.

I'll try -- but before I do, I've just removed a couple of custom
stanzas from /etc/devd.conf (after noting that updating to r241776 does
not appear to have affected the reported symptoms).  So if the removal
avoids the problem, that may reduce the searching a fair bit. :-)
(I'm also informed by my spouse that I'm to help her prepare for
some expected rain today; this may reduce the amount of time I am
able to spend on it.)

Adding the above-cited stanzas to devd.conf is one of the few things
that I did on the laptop that I haven't done elsewhere -- and while
I only track stable/9 daily on a couple of machines, I have 3 more
that I update Sunday mornings .... which would be now.  We shall
see. :-}

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
Taliban: Evil men with guns afraid of truth from a 14-year old girl.

See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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