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Date: Mon, 26 Nov 2012 18:18:43 +0400
From: Cyrill Gorcunov <gorcunov@openvz.org>
To: Amnon Shiloh <u3557@miso.sublimeip.com>
Cc: Andrey Wagin <avagin@gmail.com>, Oleg Nesterov <oleg@redhat.com>,
        Pavel Emelyanov <xemul@parallels.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: vdso && cr (Was: arch_check_bp_in_kernelspace: fix the range
 check)
Message-ID: <20121126141843.GE10312@moon>
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On Mon, Nov 26, 2012 at 11:55:01PM +1100, Amnon Shiloh wrote:
> 
> You could of course keep that old code and modify only the very
> first instruction of each routine into a jump instruction, but then
> the code to which the process returns may not be compatible with
> the new kernel and/or hardware configuration.

For sure there will be some limitations but I fear we can't do
that much with it. I don't expect the regular program to use
sigreturn for jumping into vdso code, but I could be wrong.

	Cyrill