From: Roman Zippel <zippel@linux-m68k.org>
To: Ken Ashcraft <kash@stanford.edu>
Cc: linux-kernel@vger.kernel.org, engler@stanford.edu
Subject: Re: null pointer questions
Date: Sat, 03 Nov 2001 00:20:44 +0100 [thread overview]
Message-ID: <3BE32A4C.9F9DBCC3@linux-m68k.org> (raw)
In-Reply-To: <Pine.GSO.4.33.0111021433590.6907-100000@saga18.Stanford.EDU>
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
next prev parent reply other threads:[~2001-11-02 23:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-11-02 7:30 null pointer questions Ken Ashcraft
2001-11-02 12:51 ` Roman Zippel
2001-11-02 13:16 ` lkml user
2001-11-02 22:42 ` Ken Ashcraft
2001-11-02 23:20 ` Roman Zippel [this message]
2001-11-02 23:37 ` Brian Gerst
2001-11-02 23:39 ` Brian Gerst
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