Re: kernel unaligned acc on Alpha

[Marc Giger <gigerstyle@gmx.ch>]

Hi Måns,

On Sun, 29 Feb 2004 22:24:45 +0100
mru@kth.se (Måns Rullgård) wrote:

> Marc Giger <gigerstyle@gmx.ch> writes:
> 
> > Hi All,
> >
> > I have a lot of unaligned accesses in kernel space:
> >
> > kernel unaligned acc    : 2191330
> > (pc=fffffffc002557d8,va=fffffffc00256059)
> >
> > It seems to be located in the networking part (iptables?) from the
> > kernel. Can someone please help me how to find the location of these
> > uac's? I already have recompiled the kernel with debugging enabled
> > and tried to debug it with gdb. 
> 
> Find the matching function in System.map.  Look for the entry with the
> highest address less than or equal to the pc value.

The highest address in System.map is 
fffffc000076fab0 A _end

/proc/ksyms is more informative. It seems the function is in a
module.

fffffffc00254800 ipt_unregister_table   [ip_tables]
fffffffc00256051 __insmod_ip_tables_S.rodata_L16        [ip_tables]

ipt_unregister_table is the most matching funtion, but makes no sense to
me, since I don't load and unload it 2191330 times:-)

Do you have more tips how to find the right funtion in the modules?

> 
> > Another question: What's the meaning of va?
> 
> It's the virtual memory address being accessed.  The va value is
> rather close to the pc, so I would guess that it is some static data
> from the same source file as the function that is being accessed.

Thank you very much for your help!

Regards

Marc