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Subject: Re: [patch 13/16] x86/ldt: Introduce LDT write fault handler
To: Thomas Gleixner <tglx@linutronix.de>,
        Linus Torvalds <torvalds@linux-foundation.org>
References: <20171212173221.496222173@linutronix.de>
 <20171212173334.345422294@linutronix.de>
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Cc: LKML <linux-kernel@vger.kernel.org>,
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From: Dave Hansen <dave.hansen@intel.com>
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Date: Tue, 12 Dec 2017 12:21:07 -0800
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On 12/12/2017 11:21 AM, Thomas Gleixner wrote:
> The only critical interaction is the return to user path (user CS/SS) and
> we made sure with the LAR touching that these are precached in the CPU
> before we go into fragile exit code.

How do we make sure that it _stays_ cached?

Surely there is weird stuff like WBINVD or SMI's that can come at very
inconvenient times and wipe it out of the cache.