[Etherboot-developers] signed comparison bug

[Philip R. A. <pr...@eg...>]

Hi Etherboot folks,
	I recently came across a bug in the kernel loading code 
in 4.6.7 that seems to be still present in 5.0.5. I haven't tested the 
later one, but that part of the code is the same.

The problem is the unsigned short block number, prevblock is being promoted 
to signed int in a comparison :


main.c:656
 if ((block || bcounter) && (block != prevblock+1)) {
                        /* Block order should be continuous */
                        tp.u.ack.block = htons(block = prevblock);
                }


 if ((block || bcounter) && (block != (unsigned short) (prevblock+1))) {


fixes the problem. It was preventing the block number roll over from working.

(tftpd version also needs to be 0.17 or greater, it has a similar problem).



Cheers,


Phil

-- 
Philip R. Auld, Ph.D.                  Technical Staff 
Egenera Corp.                        pa...@eg...
165 Forest St., Marlboro, MA 01752       (508)786-9444