Description of problem:
I was trying to attach to my running systemtap process, but I get a strange error "Cannot access memory", followed by "A program is being debugged already".

Version-Release number of selected component (if applicable):
gdb-7.0.50.20100203-15.fc13.i686
kernel-2.6.33-1.fc13.i686
kernel-devel-2.6.33-1.fc13.i686
systemtap-1.2-1.fc13.i686
systemtap-debuginfo-1.2-1.fc13.i686
systemtap-runtime-1.2-1.fc13.i686

How reproducible:
100%

Steps to Reproduce:
1. Run a simple systemtap command, like:
   $ stap -ve 'probe begin { println("hi") }'
2. Wait until stap has reached the point that it prints "hi".
   (It will wait here until signaled with ctrl-c)
3. Try to attach gdb to the stap process

NB: stap needs kernel-devel installed.  You also need to either be in the stapdev group or run it as root.
  
Actual results:

$ gdb stap `pgrep -x stap`
GNU gdb (GDB) Fedora (7.0.50.20100203-15.fc13)
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i686-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/bin/stap...Reading symbols from /usr/lib/debug/usr/bin/stap.debug...done.
done.
Attaching to program: /usr/bin/stap, process 1886
Cannot access memory at address 0xdef0e900
A program is being debugged already.  Kill it? (y or n) n
Program not killed.
(gdb) bt
#0  0x001d4416 in ?? ()
#1  0x003f2f63 in ?? ()
#2  0x006c0c0e in ?? ()
#3  0x00608ba2 in ?? ()
#4  0x00368c96 in ?? ()
#5  0x005ffb31 in ?? ()

Expected results:
An attached, working debugger.  And ponies.

Additional info:
Running stap and gdb as root still fails.
Running selinux-permissive still fails.
x86_64 works fine.
Rawhide works fine.