Re: Stack clobbering bug

[Richard Stallman]

      #2  0x00800040 in ?? ()
      Cannot access memory at address 0x40038

That "Cannot access memory" suggests that the stack is clobbered.  On
some platforms, with some kinds of optimization, there is no frame
pointer and chasing the stack requires some additional info.
However, aside from such cases, the lack of debug info for a library
should not stop GDB from finding and displaying further frames.
So I think the stack is clobbered, as it was in my case.

    i haven't looked further.  what is a good way
    to get more useful info than this from gdb?

The first thing to do is x/20xw  $sp
and then repeat x/20xw a few times
to see if part of the stack is clobbered with -1.

However, I suspect that the way to debug this is to try
the sources from various different dates, and determine
which change made the problem start to happen.