----- Original Message -----
 Thanks for giving me a backtrace. It helps a lot.
 
 It looks to me that restore_frame_pointer() loops here during the
 trivial operation of tracing frame pointers on the stack.
 
 I guess from the situation that the values of frame pointer are
 looping on the kernel stack. Some of a serise of frame pointers are
 broken?
 
 >
 > If you're still interested, I can make the vmlinux/vmcore available
 > to you.
 
 I'm still interested in that. Could you provide me with them? I need
 to figure out exact situtation of kernel stack relevant to the
 behaviour of restore_frame_pointer().
 
 Thanks,
 HATAYAMA Daisuke 
OK, I'll send the details off-list.
Thanks, 
  Dave