Subject: Re: PR 36963
To: None <tech-kern@netbsd.org>
From: Jordan Gordeev <jgordeev@dir.bg>
List: tech-kern
Date: 09/19/2007 10:20:38
David Holland wrote:
> 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...
> 
One good way to collect more information would be to use ktrace or truss.