Re: something really screwed up with mmap+ffs on 5.0_STABLE

[Antti Kantee <pooka%cs.hut.fi@localhost>]

[whoops, resending with tech-kern cc'd]

On Thu Aug 19 2010 at 11:17:55 +0100, Patrick Welche wrote:
> On Tue, Aug 17, 2010 at 11:52:31PM +0300, Antti Kantee wrote:
> > On Tue Aug 17 2010 at 19:06:38 +0300, Antti Kantee wrote:
> > It would be great if someone could confirm or debunk this on -current
> > and for archs beyond i386.  Just get the latest sources, go to
> > sys/rump/net/lib/libshmif, comment out line 61 (the one with PREFAULT_RW)
> > from if_shmif.c, "make && make install", and run tests/net/icmp/t_ping
> > floodping in a loop.  You should see a coredump within a few thousand
> > iteratios (few minutes) if the problem is there.
> 
> Sure enough:

Cool, thanks for confirming.

> 826:arp info overwritten for 1.1.1.10 by b2:a0:61:b4:bc:6f

I forgot to mention to remove the busfile in between runs.  Otherwise
tests will pick up on traffic from an old test run.  But this doesn't
affect the result we're after, just creates noise.

> panic: kernel diagnostic assertion "busmem->shm_magic == SHMIF_MAGIC" failed: 
> fi
> le "/sys/rump/net/lib/libshmif/if_shmem.c", line 285
> Abort trap (core dumped)
> while ( 1 )
> 827:panic: kernel diagnostic assertion "sp.sp_len < BUSMEM_DATASIZE" failed: 
> fil
> e "/usr/src/sys/rump/net/lib/libshmif/shmif_busops.c", line 135
> Abort trap (core dumped)
> while ( 1 )
> 828:panic: kernel diagnostic assertion "busmem->shm_magic == SHMIF_MAGIC" 
> failed
> : file "/sys/rump/net/lib/libshmif/if_shmem.c", line 388
> 
> though again on i386.

5.99.latest?