Martijn van Oosterhout kleptog at
Wed Jul 17 10:49:53 EST 2002

On Tue, Jul 16, 2002 at 02:44:56PM -0700, luis herrada wrote:
> Hello, I am new in this list and I'd like to know if
> there is anyone who has used the header uaccess.h
> which is included with the sources in my Red Hat 6.2
> I am just learning about the design of device drivers
> under Linux so I wanted to compile a simple program
> that detects a hardware (in this case a plain memory
> address). Everything was going fine until I ran into
> the functions copy_to_user and copy_from_user which
> are defined in the header uaccess.h.

Is this a user-space program or a kernel module? Those functions are for
kernel modules only and even then only for processing parameters from user

> I received an error message from this header that says
> "Deference pointer ..." in the function verify_area.
> Errors in my source code can be corrected but errors
> in the headers are not easy to solve because I didn't
> write them.
> Has any of you had problems like this one using this
> horrible library?
> I am using the Kernel version 2.2.14.
> I can send the source code if required.

Horrible library? It's a set of functions for a very specific purpose. If
it's a user-space program and you are directly #include ing files from
either asm/ or linux/, you're almost certainly doing something wrong.

I think you need to be more specific.
Martijn van Oosterhout   <kleptog at>
> There are 10 kinds of people in the world, those that can do binary
> arithmetic and those that can't.

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