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From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 12 Jan 2018 11:44:48 -0800
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Subject: Re: Linux 4.15-rc7
To: Pavel Machek <pavel@ucw.cz>
Cc: Arnd Bergmann <arnd@arndb.de>,
        Olivier Galibert <galibert@pobox.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        jikos@suse.cz
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On Fri, Jan 12, 2018 at 11:38 AM, Pavel Machek <pavel@ucw.cz> wrote:
>
> I'll try to do the right thing. OTOH... I don't like the fact that
> kernel memory on my machine is currently readable, probably even from
> javascript.

Oh, absolutely. I'm just saying that it's probably best to try to
start from the x86-64 KPTI model, and see how that works for x86-32.

Maybe some of the 4G:4G entry code could come in handy as a "these are
the issues" kind of thing.

> I tried disabling CPU caches. Just like that, off, boom. My system
> will not survive that, and it looks like 100x slowdown.

Yeah, no. That is not a realistic thing to do on any hardware since
the PPro, I'm afraid.

           Linus