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Date:   Fri, 26 Jan 2018 13:36:16 +0100
From:   Joerg Roedel <joro@8bytes.org>
To:     Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc:     Nadav Amit <nadav.amit@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>,
        "H . Peter Anvin" <hpa@zytor.com>,
        the arch/x86 maintainers <x86@kernel.org>,
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        "open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andy Lutomirski <luto@kernel.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Juergen Gross <jgross@suse.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Brian Gerst <brgerst@gmail.com>,
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        Andrea Arcangeli <aarcange@redhat.com>,
        Waiman Long <llong@redhat.com>, jroedel@suse.de
Subject: Re: [RFC PATCH 00/16] PTI support for x86-32
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Hi Alan,

On Thu, Jan 25, 2018 at 05:09:25PM +0000, Alan Cox wrote:
> On Mon, 22 Jan 2018 09:56:25 +0100
> Joerg Roedel <joro@8bytes.org> wrote:
> 
> > Hey Nadav,
> > 
> > On Sun, Jan 21, 2018 at 03:46:24PM -0800, Nadav Amit wrote:
> > > It does seem that segmentation provides sufficient protection from Meltdown.  
> > 
> > Thanks for testing this, if this turns out to be true for all affected
> > uarchs it would be a great and better way of protection than enabling
> > PTI.
> > 
> > But I'd like an official statement from Intel on that one, as their
> > recommended fix is still to use PTI.
> 
> It is: we don't think segmentation works on all processors as a defence.

Thanks for checking and the official statement. So the official
mitigation recommendation is still to use PTI.


Regards,

	Joerg