Thread

Re: [HACKERS] Buffer overuns with the Electric fence debugging library

Darren King <darrenk@insightdist.com> — 1998-03-18T15:39:51Z

> 
> The errors are all found in the DataFill function called from
> heap_from_tuple.
> 

Where specifically in DataFill?

> 
> Do you guys feel comfortable with a database which has reproducible
> buffer overuns?
> 
> I think it would be great is somebody who has more experience with
> postgresql than I were to look at this.
> 

This might be by design.  Check out include/access/htup.h and look at
how the tuple is defined.  Basically, there is a struct with the 
necessary header fields that is used to cast an area of memory that
has been [p]alloc'd.  See heap_addheader as an example...

Note that this technique has been declared as "Bad" by the C standards
committee, but it works and there are other things more broken.

darrenk