Panic in 6.2-PRERELEASE with bge on amd64

[Sven Willenberger]

On Tue, 2007-01-09 at 11:50 -0500, John Baldwin wrote:
> On Tuesday 09 January 2007 09:37, Sven Willenberger wrote:
> > On Tue, 2007-01-09 at 12:50 +1100, Bruce Evans wrote:
> > > On Mon, 8 Jan 2007, Sven Willenberger wrote:
> > > 
> > > > On Mon, 2007-01-08 at 16:06 +1100, Bruce Evans wrote:
> > > >> On Sun, 7 Jan 2007, Sven Willenberger wrote:
> > > 
> > > >>> The short and dirty of the dump:
> > > >>> ...
> > > >>> --- trap 0xc, rip = 0xffffffff801d5f17, rsp = 0xffffffffb371ab50, rbp 
> = 0xffffffffb371aba0 ---
> > > >>> bge_rxeof() at bge_rxeof+0x3b7
> > > >>
> > > >> What is the instruction here?
> > > >
> > > > I will do my best to ferret out the information you need. For the
> > > > bge_rxeof() at bge_rxeof+0x3b7 line, the instruction is:
> > > >
> > > > 0xffffffff801d5f17 <bge_rxeof+951>:     mov    %r15,0x28(%r14)
> > > > ...
> > > >> Looks like a null pointer panic anyway.  I guess the instruction is
> > > >> movl to/from 0x28(%reg) where %reg is a null pointer.
> > > >>
> > > >
> > > > from the above lines, apparently %r14 is null then.
> > > 
> > > Yes.  It's a bit suprising that the access is a write.
> > > 
> > > >>> ...
> > > >>> #8  0xffffffff801db818 in bge_intr (xsc=0x0) 
> at /usr/src/sys/dev/bge/if_bge.c:2707
> > > >>
> > > >> What is the statement here?  It presumably follow a null pointer and 
> only
> > > >> the exprssion for the pointer is interesting.  xsc is already null but
> > > >> that is probably a bug in gdb, or the result of excessive optimization.
> > > >> Compiling kernels with -O2 has little effect except to break debugging.
> > > >
> > > > the block of code from if_bge.c:
> > > >
> > > >   2705         if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
> > > >   2706                 /* Check RX return ring producer/consumer. */
> > > >   2707                 bge_rxeof(sc);
> > > >   2708
> > > >   2709                 /* Check TX ring producer/consumer. */
> > > >   2710                 bge_txeof(sc);
> > > >   2711         }
> > > 
> > > Oops.  I should have asked for the statment in bge_rxeof().
> > 
> > #7  0xffffffff801d5f17 in bge_rxeof (sc=0xffffffff8836b000) 
> at /usr/src/sys/dev/bge/if_bge.c:2528
> > 2528                    m->m_pkthdr.len = m->m_len = cur_rx->bge_len - 
> ETHER_CRC_LEN;
> > 
> > (where m is defined as:
> > 2449                 struct mbuf             *m = NULL;
> > )
> 
> It's assigned earlier in between those two places.  Can you 'p rxidx' as well 
> as 'p sc->bge_cdata.bge_rx_std_chain[rxidx]' and 'p 
> sc->bge_cdata.bge_rx_jumbo_chain[rxidx]'?  Also, are you using jumbo frames 
> at all? 
> 

(kgdb) p rxidx
$1 = 499
(kgdb) p sc->bge_cdata.bge_rx_std_chain[rxidx]
$2 = (struct mbuf *) 0xffffff0097a27900
(kgdb) p sc->bge_cdata.bge_rx_jumbo_chain[rxidx]
$3 = (struct mbuf *) 0x0

And no, I am not using jumbo frames:
bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=1b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING>

Sven