kernel debugging

[UmaMaheswari Devi <uma@cs.unc.edu>]

I am new to kernel hacking and am facing problems in trying to peek at the
runtime values of some kernel variables using gdb.

I am issuing the gdb command as follows:
     gdb vmlinux /proc/kcore
This displays the message
    /proc/kcore: Operation not permitted
before the (gdb) prompt is displayed.
gdb then prints a value of 0 for any valid variable that is requested.

vmlinux appears to be OK, as gdb correctly identifies undefined variables.
The problem seems to be with /proc/kcore. This file has a permission of 400. I
am using the Red Hat distribution.

Any help is appreciated. 

Thanks,
Uma.