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Date: Sat, 03 Nov 2001 00:20:44 +0100
From: Roman Zippel <zippel@linux-m68k.org>
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To: Ken Ashcraft <kash@stanford.edu>
CC: linux-kernel@vger.kernel.org, engler@stanford.edu
Subject: Re: null pointer questions
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Hi,

Ken Ashcraft wrote:

> Why does it matter if 0 is a valid user space or not?  If I make the call
> 
> copy_from_user(0, user_ptr, 4);
> 
> the null pointer is the kernel address, not the user address.  Can you
> clarify please?

Sorry, I misunderstood you. The kernel address has to be a valid address
of course, otherwise the behavior is undefined.

bye, Roman