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From: mouse@mcgill-vision.UUCP
Newsgroups: net.unix-wizards
Subject: Re: Process Execution with Non-Standard Entry Points
Message-ID: <354@mcgill-vision.UUCP>
Date: Sun, 26-Jan-86 19:15:53 EST
Article-I.D.: mcgill-v.354
Posted: Sun Jan 26 19:15:53 1986
Date-Received: Fri, 31-Jan-86 23:43:41 EST
References: <1867@brl-tgr.ARPA>
Organization: McGill University, Montreal
Lines: 37

key:
> yamo@ames-nas.arpa (Michael J. Yamasaki)
>>> yamo attributes to jth@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

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