Re: kern/54897 (ipsec tests now fail randomly on real hardware)

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

The following reply was made to PR kern/54897; it has been noted by GNATS.

From: Ryota Ozaki <ozaki-r%netbsd.org@localhost>
To: Andreas Gustafsson <gson%gson.org@localhost>
Cc: "gnats-bugs%NetBSD.org@localhost" <gnats-bugs%netbsd.org@localhost>
Subject: Re: kern/54897 (ipsec tests now fail randomly on real hardware)
Date: Thu, 20 Feb 2020 17:30:24 +0900

 On Tue, Feb 18, 2020 at 3:46 AM Andreas Gustafsson <gson%gson.org@localhost> wrote:
 >
 > Ryota Ozaki wrote:
 > >  Module Name: src
 > >  Committed By:        ozaki-r
 > >  Date:                Mon Feb 17 08:46:10 UTC 2020
 > >
 > >  Modified Files:
 > >       src/tests/net/ipsec: t_ipsec_gif.sh t_ipsec_l2tp.sh
 > >
 > >  Log Message:
 > >  tests: add missing ifconfig -w
 > >
 > >  This change mitigates PR kern/54897.
 > >
 > >
 > >  To generate a diff of this commit:
 > >  cvs rdiff -u -r1.8 -r1.9 src/tests/net/ipsec/t_ipsec_gif.sh \
 > >      src/tests/net/ipsec/t_ipsec_l2tp.sh
 >
 > This made no difference as far as I can see.  In the first test run
 > of my testbed after the above commit, four ipsec test cases failed:
 >
 >   http://www.gson.org/netbsd/bugs/build/amd64-baremetal/commits-2020.02.html#2020.02.17.08.46.10
 >
 > which is the same number as in the last run before the commit
 > (2020.02.17.06.32.46).
 
 Yes.  I was misguided.  The number of failures varies and is sometimes
 quite small.
 
 I found a real issue (hopefully correct this time) that is MAC address
 duplication;
 shmif interfaces on rump kernels sometimes had an identical MAC address
 because cprng_fast32 used for MAC address generations sometimes returned
 identical bytes.
 
 Fixing the issue would reduce the number of test failures but not resolve them
 all yet.  There still remain other cause(s).  (Maybe that is a real cause of
 cprng_fast32 breakage on rump kernels.)
 
   ozaki-r