Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!cam-cl!maj
From: maj@cl.cam.ac.uk (Martyn Johnson)
Newsgroups: comp.unix.ultrix
Subject: Re: Can't get a core file
Summary: It is a kernel bug
Keywords: coredump kernel
Message-ID: <1682@gannet.cl.cam.ac.uk>
Date: 6 Dec 89 09:49:55 GMT
References: <1197@umigw.MIAMI.EDU>
Sender: news@cl.cam.ac.uk
Organization: U of Cambridge Comp Lab, UK
Lines: 21

VAX Ultrix 3.0 had at least two kernel bugs which messed up core dumps. 
One of these provoked exactly the effect you describe; it was a vulgar 
bug in the access checking routines which were confused by the EINTR 
lying around in u.u_error.

Digital fixed at least one, possibly both, of the bugs on the VAX in 
maintenance release 3.1 (the reason I'm not sure is that I actually fixed 
them myself in the source and still run 3.0).

The fixes don't seem to have reached RISC Ultrix.  The problem you 
describe is present in release 3.1A for the 5400.  The fixes are trivial 
at the source level, so all it takes is for somebody to persuade Digital 
to actually release a patch or something.

Martyn Johnson      maj@cl.cam.ac.uk
University of Cambridge Computer Lab
New Museums Site
Pembroke Steet
Cambridge
CB2 3QG
UK