Process Execution with Non-Standard Entry Points

[mouse at mcgill-vision.UUCP]

key:
> yamo at ames-nas.arpa (Michael J. Yamasaki)
>>> yamo attributes to jth at linus.UUCP (Joseph T. Healey)

>>> I am interested in taking a "snapshot" of a running process,
>>> stopping execution and then resuming execution at the instruction
>>> after the stop. I have successfully [ attempted to build a new
>>> a.out ]
>>> [ but the new a.out segmentation faults ]
>
> I missed the original article, but ...

     I'm afraid I did too.  Miss the original, that is.  But the request
seems clear enough.

> It seems that what you might be interested in is ptrace(2).

     Ptrace might be used to  do this,  but  it can get awkward.   I put
this  in our kernel; it isn't very difficult (4.2bsd) if you have kernel
source.  Unfortunately, you cannot have ANY  files open at the time  you
make the dump (open files looked like too much of a headache to save the
state of,  so  I let the programmer  worry about closing  and re-opening
files).  It works OK; people  here use it  as a checkpoint mechanism for
programs  which take  cpu-hours or  cpu-days.   If  anyone out  there is
interested, mail me (see  the  .signature  below)  and I  can  give  you
details, or if you have a  source license we can work  out something for
getting you the code.
-- 
					der Mouse

USA: {ihnp4,decvax,akgua,etc}!utcsri!mcgill-vision!mouse
     philabs!micomvax!musocs!mcgill-vision!mouse
Europe: mcvax!decvax!utcsri!mcgill-vision!mouse
        mcvax!seismo!cmcl2!philabs!micomvax!musocs!mcgill-vision!mouse

Hacker: One who accidentally destroys /
Wizard: One who recovers it afterward