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Date: Tue, 17 May 2011 03:10:06 +0100
From: Matthew Garrett <mjg@redhat.com>
To: Fenghua Yu <fenghua.yu@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
        H Peter Anvin <hpa@zytor.com>,
        Asit K Mallick <asit.k.mallick@intel.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Avi Kivity <avi@redhat.com>, Arjan van de Ven <arjan@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andi Kleen <andi@firstfloor.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 3/4] x86, head_32/64.S: Enable SMEP
Message-ID: <20110517021006.GA6732@srcf.ucam.org>
References: <1305581685-5144-1-git-send-email-fenghua.yu@intel.com>
 <1305581685-5144-4-git-send-email-fenghua.yu@intel.com>
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On Mon, May 16, 2011 at 02:34:44PM -0700, Fenghua Yu wrote:
> From: Fenghua Yu <fenghua.yu@intel.com>
> 
> Enable newly documented SMEP (Supervisor Mode Execution Protection) CPU
> feature in kernel.
> 
> SMEP prevents the CPU in kernel-mode to jump to an executable page that does
> not have the kernel/system flag set in the pte. This prevents the kernel
> from executing user-space code accidentally or maliciously, so it for example
> prevents kernel exploits from jumping to specially prepared user-mode shell
> code. The violation will cause page fault #PF and will have error code
> identical to XD violation.

Are EFI runtime service pages currently set up appropriately?

-- 
Matthew Garrett | mjg59@srcf.ucam.org
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