Hi Bruno.

Could you try running with the attached patch?  This debug patch is
built against the linux-2.6.31.9 kernel.  I think the panic is occuring
right before a reset has occured due to a TX timeout.  To see if this is
happening, this patch will print hardware state information when a TX
timeout occurs.  If you could run with this patch and send the logs when
the panic occurs, I would really appreciate it.

Thanks again.

-Ben

On Tue, 2009-12-29 at 05:54 -0800, Bruno Prémont wrote:
> On Tue, 29 Dec 2009 01:05:40 "Benjamin Li" <benli@broadcom.com> wrote:
> > Hi Bruno,
> > 
> > It looks like the the NULL dereference is happening at a0fc.
> > 
> > a0f8:       48 8b 42 70             mov 0x70(%rdx),%rax 
> > a0fc:       0f b7 10                movzwl (%rax),%edx
> > a0ff:       31 c0                   xor    %eax,%eax
> > 
> > The offset of 0x70 is the bp field in the bnx2_napi structure.  (Seen
> > in the bnx2_napi structure dump below)  These lines are found in the
> > routine, bnx2_get_hw_tx_cons() which look like they were inlined by
> > the compiler.  More specifically it looks like the dereference of the
> > hw_tx_cons_ptr failed.
> > 
> > cons = *bnapi->hw_tx_cons_ptr;
> > 
> > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=drivers/net/bnx2.c;h=06b901152d4487fa04164437cc179661b44657fe;hb=74fca6a42863ffacaf7ba6f1936a9f228950f657#l2761
> > 
> > To be sure this is the case, could you send the .config file you are
> > using or if you could send me the bnx2 kernel module built with the
> > CFLAG '-g', then we can definitely verify where in the code it is
> > crashing.
> > 
> > Did you see anything suspicious in the system kernel logs?  If you
> > could isolate the logs from when the machine booted to when it crash
> > and send it to us it would be very helpful. 
> 
> It crashes every now and then (since netconsole is enabled it does not
> survive 24 hours :( ) while or just after transmitting log messages with
> netconsole, the messages being transmitted are logging that occurs with
> netfilter 'LOG' target.
> 
> Sample output as seen by netconsole recipient (1 packet per line, IP
> addresses masked):
> 
> [ 2115.949606] (reject)output: IN= OUT=eth0
> SRC=***.**.*.** DST=**.***.**.***
> LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=29589
> DF
> PROTO=TCP
> SPT=58991 DPT=80
> WINDOW=5840
> RES=0x00
> SYN
> URGP=0
> 
> [ 2115.949704] (reject)output: IN= OUT=eth0
> SRC=***.**.*.** DST=**.***.**.***
> [ 2115.949729] BUG: unable to handle kernel NULL pointer dereference at (null)
> [ 2115.949732] IP: [<ffffffffa00680fc>] bnx2_poll_work+0x2c/0x12d0 [bnx2]
> [ 2115.949742] PGD 5b6f0067 PUD 59c04067 PMD 0
> [ 2115.949744] Oops: 0000 [#1] SMP
> [ 2115.949746] last sysfs file: /sys/kernel/uevent_seqnum
> [ 2115.949749] CPU 3
> [ 2115.949750] Modules linked in: dm_round_robin scsi_dh_rdac ipmi_devintf netconsole squashfs configfs zlib_inflate ext2 loop dm_multipath scsi_dh dm_mod sg sr_mod cdrom ata_piix h
> pwdt qla2xxx ipmi_si ahci bnx2 ipmi_msghandler libata uhci_hcd ehci_hcd
> [ 2115.949764] Pid: 7926, comm: php-cgi Not tainted 2.6.31.9-x86_64 #1 ProLiant DL360 G5
> [ 2115.949766] RIP: 0010:[<ffffffffa00680fc>]  [<ffffffffa00680fc>] bnx2_poll_work+0x2c/0x12d0 [bnx2]
> 
> Looks like netpoll is triggering suicide on BNX2.
> 
> Any way to get the NULL-pointer non-fatal would help a lot! (any
> sensible thing to do when bnapi->hw_tx_cons_ptr is NULL that would
> allow the system to continue working without killing everything?)
> 
> 
> Regards,
> Bruno
>