From: Andi Kleen <ak@muc.de>
To: Eric Dumazet <dada1@cosmosbay.com>
Cc: Linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: [BUG?] x86_64 : Can not read /dev/kmem ?
Date: 21 Mar 2005 20:37:03 +0100
Date: Mon, 21 Mar 2005 20:37:03 +0100 [thread overview]
Message-ID: <20050321193703.GA2145@muc.de> (raw)
In-Reply-To: <4235695F.5070203@cosmosbay.com>
Sorry for the late answer.
On Mon, Mar 14, 2005 at 11:37:19AM +0100, Eric Dumazet wrote:
>
> Hi Andi
>
> I tried to read /dev/kmem on x86_64 (linux-2.6.11) and got no success.
>
> read() or pread() returns EINVAL
Yes. I fixed this once for 2.4, but somehow the changes never made
it into 2.6. The VFS code doesn't like negative offsets, and the kernel
addresses are negative.
>
> I tried mmap() too : mmap() calls succeed, but as soon the user process
> dereference memory, we get :
Hmm, looks like a bug yes. I can reproduce it. Thanks for the report.
Will investigate later.
-Andi
next prev parent reply other threads:[~2005-03-21 19:37 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-13 18:20 [patch] x86: fix ESP corruption CPU bug Stas Sergeev
2005-03-13 18:52 ` Grzegorz Kulewski
2005-03-13 19:11 ` Stas Sergeev
2005-03-13 19:37 ` Ondrej Zary
2005-03-13 19:46 ` Stas Sergeev
2005-03-13 20:02 ` Pavel Machek
2005-03-13 20:10 ` Pavel Machek
2005-03-13 20:55 ` Stas Sergeev
2005-03-13 21:13 ` Linus Torvalds
2005-03-13 22:06 ` [patch] x86: fix ESP corruption CPU bug (take 2) Stas Sergeev
2005-03-14 19:29 ` Alan Cox
2005-03-14 19:59 ` Stas Sergeev
2005-03-15 3:34 ` Andrew Morton
2005-03-15 10:48 ` x86: spin_unlock(), spin_unlock_irq() & others are out of line ? Eric Dumazet
2005-03-15 19:44 ` Lee Revell
2005-03-15 19:48 ` [patch] x86: fix ESP corruption CPU bug (take 2) Stas Sergeev
2005-03-13 23:17 ` [patch] x86: fix ESP corruption CPU bug Pavel Machek
2005-03-13 23:54 ` Linus Torvalds
2005-03-14 0:16 ` Linus Torvalds
2005-03-14 4:52 ` Stas Sergeev
2005-03-14 9:34 ` Andi Kleen
2005-03-14 10:37 ` [BUG?] x86_64 : Can not read /dev/kmem ? Eric Dumazet
2005-03-21 19:37 ` Andi Kleen [this message]
2005-03-22 15:24 ` Andi Kleen
2005-03-14 15:21 ` [patch] x86: fix ESP corruption CPU bug Jakob Eriksson
2005-03-14 17:03 ` linux-os
2005-03-14 17:10 ` Pavel Machek
2005-03-14 19:24 ` Brian Gerst
2005-03-14 20:21 ` Stas Sergeev
2005-03-14 18:02 ` Stas Sergeev
2005-03-14 17:29 ` Stas Sergeev
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