Where is the entry point of winding frames that are transferred to gdb in kernel src?

Hi there,

After tracing the "info all-registers" for a while, I finally found a
function doing unwinding frames that are passed from target machine (I
found an input argument is named as from_tty or something similar).
So, I have the following  queries:
  1. Where in the Kernel src is doing all these winding business?
  2. Can anyone point out to me an exact function invoked in gdb to
unwind the frames?


Thanks in advance,
-- 
James Yu (游家慶)
+886-932-353-055
[email protected]