Re: UPD: Frequent/consistent panics in 2.4.19 at ip_route_input_slow, in_dev_get(dev)

[Alain Fauconnet <alain@cscoms.net>]

Hello,

On Mon, Oct 21, 2002 at 08:40:16PM +0400, kuznet@ms2.inr.ac.ru wrote:
> 
> Try better to enable slab poisoning in slab.h. If it that thing
> which I think of, it would provoke crash.
> 
> Alexey
> 

I have got a new crash on the same box with CONFIG_DEBUG_SLAB=y
(reminder: Kernel 2.4.19)

Unable to handle kernel paging request at  virtual address 5a5a5a5e

EIP : 0010:[<c02318a9>] <ip_route_input_slow+33>
EAX : 00000000   EBX : 5a5a5a5a   ECX : 9c515bec
EDX : 5a5a5a5a   ESI : ccb5b542   EDI : d71a10ac
EBP : c1aae690   ESP : c02f3e44

Process Swapper (pid: 0, stackpage = c02f3000)

Stack: 5a5a5a   ccb5b542   d71a10ac   c1aae690
(sorry, first stack word was written down incorrectly by operator, one
byte lost)

Call Trace:
[<c010980d>] <get_irq_list+137>
[<c0109a71>] <do_IRQ+133>
[<c02321ca>] <ip_route_input+338>
[<c02342e4>] <ip_rcv_finish+40>

(I find this stack trace strange. Once again I  haven't  written  this
down myself so I can't be sure it's 100% accurate)


Code : ff 42 04 b8 54 24 24 89 54 24 28 c7 44 24 20 00 00 00 00 c7

Still the same exact place in ip_route_input_slow:

(gdb) x/i 0xc02318a9
0xc02318a9 <ip_route_input_slow+33>:    incl   0x4(%edx)
0xc02318ac <ip_route_input_slow+36>:    mov    0x24(%esp,1),%edx
0xc02318b0 <ip_route_input_slow+40>:    mov    %edx,0x28(%esp,1)
0xc02318b4 <ip_route_input_slow+44>:    movl   $0x0,0x20(%esp,1)
0xc02318bc <ip_route_input_slow+52>:    movl   $0x0,0x38(%esp,1)
0xc02318c4 <ip_route_input_slow+60>:    movl   $0x0,0x34(%esp,1)

It looks to me that the value in DX is "poisoned" data isn't it?
I assume that the kernel is trying to use dynamic memory that has been
released already, right?

What's next in tracing this one down?

Thanks for any hint,
_Alain_