Date: Tue, 9 Jan 2007 14:09:29 -0500 From: John Baldwin <jhb@freebsd.org> To: Sven Willenberger <sven@dmv.com> Cc: stable@freebsd.org, freebsd-amd64@freebsd.org Subject: Re: Panic in 6.2-PRERELEASE with bge on amd64 Message-ID: <200701091409.29828.jhb@freebsd.org> In-Reply-To: <1168365209.29047.23.camel@lanshark.dmv.com> References: <1168211205.22629.6.camel@lanshark.dmv.com> <200701091150.15274.jhb@freebsd.org> <1168365209.29047.23.camel@lanshark.dmv.com>
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On Tuesday 09 January 2007 12:53, Sven Willenberger wrote:
> 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>
Did you do a 'p m' to verify that m is NULL? If you can reproduce this, I'd
add some KASSERT's where it fetches the mbuf out of the descriptor data to
see if m is NULL.
--
John Baldwin
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