Re: Validating Pointers

tpepper
2001-07-26T17:10:11Z

On Thu 26 Jul at 16:52:48 +0100 alan@lxorguk.ukuu.org.uk done said:
> access_ok may do minimal checks, or no checking at all. The only point at
> which you can validate a user point is when you use copy*user and
> get/put_user to access the data.

Should the i386 access_ok() fail when checking a copy to/from userspace
from/to a static in a driver module? The __copy_to|from_user work fine
and copy_to|from_user fail, but I guess that doesn't mean access_ok()
is the culprit. I don't know intel assembly and the platforms for
which I do get the assembly don't do much in access_ok() so there's no
comparing...but I'd have thought they'd be more concerned with the user
address location than the kernel one.

t.