The file malloc.ci.auis6.3.diff is a patch submitted by wdc@mit.edu to fix the problem described below.  This patch is to be applied to the the file overhead/malloc/malloc.ci in AUIS versions up to and including 6.3.  Instructions for applying patches are located on the ftp server ftp.andrew.cmu.edu in pub/AUIS/patches/official/README.  

PROBLEM FIXED BY THIS PATCH:

The computation of the arena size in addarena was incorrect.        
It was telling us how many objects of the size of freehdr would
fit in the arena when we wanted to know how many bytes were there.

This problem was non-toxic until gcc 2.6 which takes ANSI C at it's
word:  The results are undefined if you do pointer arithmetic on
elements of an array that are not aligned on the unit of the size of
the array elements.

When we asked how many 24 byte structures fit between arenaend and
arenastart, ANSI says it's ok to come back with garbage when 
arenaend or arenastart are not aligned on a 24 byte boundry.