Re: kern/46083: gem(4) is broken on NetBSD 6_BETA (macppc)

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

The following reply was made to PR kern/46083; it has been noted by GNATS.

From: Valery Ushakov <uwe%stderr.spb.ru@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/46083: gem(4) is broken on NetBSD 6_BETA (macppc)
Date: Mon, 16 May 2016 15:01:38 +0300

 On Mon, May 16, 2016 at 10:35:01 +0000, Valery Ushakov wrote:
 
 >  I've noticed this too.  It looks like under load gem(4) also starts
 >  sending garbled ethernet frames from time to time, that have random 2,
 >  4 or 6 bytes prepended to them.  In the latter case the destination
 >  address shifts into the position of the source address, so the
 >  receiver gets confused and complains about frames from itself.
 
 Looking closer, I can see 5 and 7 bytes prefixes too.
 
 I can also see that bogus prefixes are actually suffixes of other
 frames.  E.g. I had a bulk scp providing load to trigger the bug and
 also had a ping running in parallel.  There're quite a few bad frames
 that start with "234567", "4567", "67" - which is what ping payload
 ends with.  There are some packets where I can guess the bogus prefix
 is the suffix of an irc ping packet (in the 6 byte prefix there's
 enough info to guess, and then infer for shorter prefixes/suffixes).
 
 -uwe