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From: Linus Torvalds <torvalds@linux-foundation.org>
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
Subject: Re: Linux 4.15-rc7
Date: Fri, 12 Jan 2018 11:44:48 -0800	[thread overview]
Message-ID: <CA+55aFyDtWAOaXZuNtCFb=a1MAazxcZ02ut-RkOqGj4mcXyNYA@mail.gmail.com> (raw)
In-Reply-To: <20180112193815.GA4918@amd>

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

  reply	other threads:[~2018-01-12 19:44 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-07 22:55 Linux 4.15-rc7 Linus Torvalds
2018-01-08  7:20 ` Thomas Gleixner
2018-01-10 23:32 ` Pavel Machek
2018-01-11 11:29   ` Olivier Galibert
2018-01-11 14:06     ` Nikolay Borisov
2018-01-12 11:06     ` Pavel Machek
2018-01-12 13:23       ` Arnd Bergmann
2018-01-12 14:43         ` Pavel Machek
2018-01-12 17:20         ` vcaputo
2018-01-12 20:11           ` Arnd Bergmann
2018-01-12 22:04             ` vcaputo
2018-01-12 22:08               ` Arnd Bergmann
2018-01-12 22:58                 ` vcaputo
2018-01-12 17:34         ` Linus Torvalds
2018-01-12 19:38           ` Pavel Machek
2018-01-12 19:44             ` Linus Torvalds [this message]
2018-01-12 20:41               ` Pavel Machek
2018-01-13 12:52               ` kernel page table isolation for x86-32 was " Pavel Machek
2018-01-11 14:07   ` Jiri Kosina
2018-01-19 10:28     ` Pavel Machek

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