[lug] System.map

[Rob Riggs]

"Stephen G. Smith" wrote:
> 
> Will someone explain sysmap.map?
> What does it do?
> 
> On a new kernel install, is a new one generated?
> 
> I have a new kernel installed now and I get a message that
> the System.map lists the wrong kernel version..

The System.map file lists the addresses of kernel functions and
static data areas, so that programs like 'ps' can determine what
kenrel function a process may be sleeping in. If run 'ps -aelf',
for instance, it lists a WCHAN column with a function name. This
is the function that the process is sleeping in.

The System.map is also used to decode the traceback that the kernel
emits when the kernel has an exception (or "kernel oops"). The newer
syslogd can do this, provided a System.map is installed.

Having a System.map installed that does not coorespond to your
running kernel can cause all sorts of confusion when trying to
track down obscure system problems.

-- 
Rob Riggs
Technical Staff
Tummy.com, Ltd.
http://www.tummy.com/