Subject: Re: PR 36963
To: Jan Danielsson <jan.m.danielsson@gmail.com>
From: David Holland <dholland+netbsd@eecs.harvard.edu>
List: tech-kern
Date: 09/18/2007 21:00:45
On Wed, Sep 19, 2007 at 02:39:02AM +0200, Jan Danielsson wrote:
 > http://www.netbsd.org/cgi-bin/query-pr-single.pl?number=36963
 > [...]

Are you running a multiprocessor kernel?

(And if you haven't yet, try turning on DIAGNOSTIC and LOCKDEBUG.)

 >    I would just like to check if anyone has any interest in this
 > problem. 

Definitely - the more information you can collect, the better.

One useful thing to find out would be whether, after things stop
working, the process credentials stored in the kernel are still
correct or if they've been garbaged. When things break, does running
"id" print right or wrong information? Also, does ls -l (or
stat(2)/fstat(2) if necessary(*)) return the right owner/group and
permissions for the affected files?


(*) E.g., if once it breaks you can't ls -l, or even call stat()
successfully, you can write a program that opens the file (or
directory) before things break, waits until they do, and then uses
fstat() on that file handle. This should get past any broken
permissions checks. It might also conceivably prevent the problem from
affecting the file in question...

-- 
   - David A. Holland / dholland+netbsd@eecs.harvard.edu