From mboxrd@z Thu Jan  1 00:00:00 1970
From: oleg@redhat.com (Oleg Nesterov)
Date: Tue, 15 Apr 2014 20:07:00 +0200
Subject: [RFC PATCH] uprobes: copy to user-space xol page with proper
 cache flushing
In-Reply-To: <20140415.135038.1703628429468655272.davem@davemloft.net>
References: <534D6A1F.70102@linaro.org>
 <20140415.133840.2270952586596479547.davem@davemloft.net>
 <20140415174900.GA11184@redhat.com>
 <20140415.135038.1703628429468655272.davem@davemloft.net>
Message-ID: <20140415180700.GB11690@redhat.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 04/15, David Miller wrote:
>
> From: Oleg Nesterov <oleg@redhat.com>
> Date: Tue, 15 Apr 2014 19:49:00 +0200
>
> > We do not want to write to, say, page cache if the probed application
> > mmaps a file at the same vaddr.
>
> If user has write access to that page... not our problem.

Well, I am not sure.

Yes, this won't allow you to write the exploit. But if this actually
happens because an application is buggy, this can lead to really
hard-to-debug problems.

Oleg.