kernel 2.2.19: Oops in tcp_keepalive?

[David Holland <david.holland@3glab.com>]

Hi,

I have a Sun Ultra 5 running Debian 2.2r4 acting as a very
lightly-loaded web and DNS server. It is Oops-ing roughly every couple
of hours, at which point the machine usually locks solid; not even
Stop-A gets a response. The kernel is kernel-image-2.2.19-sun4u-8. Can
anyone suggest what's causing the Oops, or how to fix it?

Here's the ksymoops'ed Oops:

ksymoops 2.3.4 on sparc64 2.2.19.  Options used
     -V (default)
     -k /proc/ksyms (default)
     -l /proc/modules (default)
     -o /lib/modules/2.2.19/ (default)
     -m /boot/System.map-2.2.19 (default)

Warning: You did not tell me where to find symbol information.  I will
assume that the log matches the kernel and modules that are running
right now and I'll use the default options above for symbol resolution.
If the current kernel and/or modules do not match the log, you can get
more accurate output by telling me the kernel version and where to find
map, modules, ksyms etc.  ksymoops -h explains the options.

No modules in ksyms, skipping objects
Warning (read_lsmod): no symbols in lsmod, is /proc/modules a valid lsmod file?
Unable to handle kernel paging request at virtual address 0000000100000000
tsk->mm->context = 0000000000000000
tsk->mm->pgd = fffff8001000ec00
swapper(0): Oops
TSTATE: 0000009980009602 TPC: 00000000004d8c74 TNPC: 00000000004d8c78 Y: 00000000
Using defaults from ksymoops -t elf32-sparc -a sparc
g0: fffff80015892000 g1: 0000000000627400 g2: 00000000001a39d8 g3: 00000000000231fa
g4: fffff80000000000 g5: 0000000000000000 g6: 0000000000414000 g7: 0000000000000001
o0: 00000000000fd188 o1: 00000000006f7400 o2: 000000000001fa32 o3: 00000000004141a0
o4: 0000000000000000 o5: 00000000700e1570 sp: 0000000000416f01 ret_pc: 0000000000027e10
l0: 0000000000000000 l1: 0000000100000000 l2: 00000000effffc10 l3: 000000000001fa31
l4: 0000000000000000 l5: 0000000000075c00 l6: 00000000006f8e58 l7: 0000000000000007
i0: 0000000000636000 i1: 00000000006f8c00 i2: 0000000000636000 i3: 0000000000000000
i4: 0000000000000000 i5: 0000000000414000 i6: 0000000000416fc1 i7: 00000000004d91e8
Instruction DUMP: 02c44055  9404e001  ae102007  <d0046048> 80a22000  1248004c  ea5c6030  d00c60bb  80a22000

>>PC;  004d8c74 <tcp_keepalive+54/200>   <=====
>>O7;  00027e10 Before first symbol
>>I7;  004d91e8 <tcp_sltimer_handler+48/c0>
Code;  004d8c68 <tcp_keepalive+48/200>
0000000000000000 <_PC>:
Code;  004d8c68 <tcp_keepalive+48/200>
   0:   02 c4 40 55       unknown
Code;  004d8c6c <tcp_keepalive+4c/200>
   4:   94 04 e0 01       add  %l3, 1, %o2
Code;  004d8c70 <tcp_keepalive+50/200>
   8:   ae 10 20 07       mov  7, %l7
Code;  004d8c74 <tcp_keepalive+54/200>   <=====
   c:   d0 04 60 48       ld  [ %l1 + 0x48 ], %o0   <=====
Code;  004d8c78 <tcp_keepalive+58/200>
  10:   80 a2 20 00       cmp  %o0, 0
Code;  004d8c7c <tcp_keepalive+5c/200>
  14:   12 48 00 4c       unknown
Code;  004d8c80 <tcp_keepalive+60/200>
  18:   ea 5c 60 30       unknown
Code;  004d8c84 <tcp_keepalive+64/200>
  1c:   d0 0c 60 bb       ldub  [ %l1 + 0xbb ], %o0
Code;  004d8c88 <tcp_keepalive+68/200>
  20:   80 a2 20 00       cmp  %o0, 0

Aiee, killing interrupt handler
Kernel panic: Attempted to kill the idle task!
In swapper task - not syncing

2 warnings issued.  Results may not be reliable.

Here's the raw Oops:

Unable to handle kernel paging request at virtual address 0000000100000000
tsk->mm->context = 0000000000000000
tsk->mm->pgd = fffff8001000ec00
(face)
swapper(0): Oops
TSTATE: 0000009980009602 TPC: 00000000004d8c74 TNPC: 00000000004d8c78 Y: 00000000
g0: fffff80015892000 g1: 0000000000627400 g2: 00000000001a39d8 g3: 00000000000231fa
g4: fffff80000000000 g5: 0000000000000000 g6: 0000000000414000 g7: 0000000000000001
o0: 00000000000fd188 o1: 00000000006f7400 o2: 000000000001fa32 o3: 00000000004141a0
o4: 0000000000000000 o5: 00000000700e1570 sp: 0000000000416f01 ret_pc: 0000000000027e10
l0: 0000000000000000 l1: 0000000100000000 l2: 00000000effffc10 l3: 000000000001fa31
l4: 0000000000000000 l5: 0000000000075c00 l6: 00000000006f8e58 l7: 0000000000000007
i0: 0000000000636000 i1: 00000000006f8c00 i2: 0000000000636000 i3: 0000000000000000
i4: 0000000000000000 i5: 0000000000414000 i6: 0000000000416fc1 i7: 00000000004d91e8
Instruction DUMP: 02c44055  9404e001  ae102007  <d0046048> 80a22000  1248004c  ea5c6030  d00c60bb  80a22000

Aiee, killing interrupt handler
Kernel panic: Attempted to kill the idle task!
In swapper task - not syncing
Press L1-A to return to the boot prom


I copied the Oops from the screen to another machine by hand so there
might be typos, though I did check it carefully.

Thanks in advance,
Dave
-- 
David Holland           =*=   Systems Manager   =*=   tel: +44 01223 478900
http://www.3glab.com/   =*=     3G Lab, UK      =*=   fax: +44 01223 478901