Subject: Re: proposal: disable *printf %n specifier in libc in NetBSD 1.5
To: Bill Sommerfeld <>
From: Greywolf <>
List: tech-userlevel
Date: 09/11/2000 23:38:45
On Mon, 11 Sep 2000, Bill Sommerfeld wrote:

# The amount of time I have for NetBSD is limited.  I can spend that
# time issuing advisories for format bugs in packages, or I can spend a
# fraction of that time preventing the entire class of bugs and have
# more time left over to work on interesting features like SMP.

Okay, time out, here.

If you want to be working on SMP, for heaven's sake, please do.  There's
nothing stopping you.

For Bill's point, he's brought up a concern which should probably be
addressed in some fashion.  Whether that fashion is in examination
or action should probably be determined by another party.  I think
most sane folks would agree that action is preferential to simple
examination in the case of our tree.

The %n thing is POSIX, yes?  We're striving to be POSIX compliant
as much as practical, yes?  So we keep the implementation, fix
the code in the tree and be done with it.  It's not our responsibility
to scan/warn of this construct in third-party software.  It's a nice
"what-if", but what if we warn on set-id, so what then?  Do you really
think it's going to provide sufficient impetus to the external authors
to get it fixed?  I somehow doubt it.  "Oh, netbsd gives us this warning,
let's stop porting it there."  Or not; I don't know for sure, but being
obnoxious about this sort of thing is not likely to win lots of friends.

A posted advisory might be a better way to deal with this.

I don't know, I'm rambling as it's late.  But I don't think I'm all
that far off the mark.  I think both sides have valid points, here,
but to claim that fixing "%n" is interfering with the ability to
do SMP sounds like a fish claiming that, for whatever reason, it
cannot ride a bicycle.

# 					- Bill

BSD:  We come in peace.  We offer reliability.