From: Andi Kleen <ak@muc.de>
To: virtualization@lists.osdl.org
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
Jeremy Fitzhardinge <jeremy@goop.org>,
Andrew Morton <akpm@osdl.org>, Chris Wright <chrisw@sous-sol.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] paravirt.h
Date: Tue, 22 Aug 2006 15:44:26 +0200 [thread overview]
Message-ID: <200608221544.26989.ak@muc.de> (raw)
In-Reply-To: <1156254965.27114.17.camel@localhost.localdomain>
I don't see why paravirt ops is that much more sensitive
than most other kernel code.
> It would be a lot safer if we could have the struct paravirt_ops in
> protected read-only const memory space, set it up in the core kernel
> early on in boot when we play "guess todays hypervisor" and then make
> sure it stays in read only (even to kernel) space.
By default we don't make anything read only because that would
mess up the 2MB kernel mapping.
In general i don't think making select code in the kernel
read only is a good idea, because as long as you don't
protect everything including stacks etc. there will be always
attack points where supposedly protected code relies
on unprotected state. If someone can write to kernel
memory you already lost.
And it adds TLB pressure.
-Andi
next prev parent reply other threads:[~2006-08-22 13:44 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-10 9:35 [PATCH] paravirt.h Rusty Russell
2006-08-10 10:10 ` Rusty Russell
2006-08-10 10:30 ` Andi Kleen
2006-08-10 11:05 ` Rusty Russell
2006-08-10 11:31 ` Andi Kleen
2006-08-10 13:03 ` Zachary Amsden
2006-08-10 15:14 ` Jeremy Fitzhardinge
[not found] ` <44DB54A5.50006@vmware.com>
[not found] ` <44DB6144.2080308@goop.org>
[not found] ` <1155262867.27719.2.camel@localhost.localdomain>
2006-08-11 2:34 ` Jeremy Fitzhardinge
2006-08-10 18:06 ` Jeremy Fitzhardinge
2006-08-19 1:21 ` Adrian Bunk
2006-08-19 2:46 ` Jeremy Fitzhardinge
2006-08-20 8:50 ` Geert Uytterhoeven
2006-08-22 12:56 ` Jeremy Fitzhardinge
2006-08-22 14:08 ` Adrian Bunk
2006-08-22 13:56 ` Alan Cox
2006-08-22 13:44 ` Andi Kleen [this message]
2006-08-22 17:16 ` Zachary Amsden
2006-08-22 18:29 ` Arjan van de Ven
2006-08-22 19:30 ` Alan Cox
2006-08-22 19:17 ` Zachary Amsden
2006-08-22 19:26 ` Zachary Amsden
2006-08-22 19:29 ` Arjan van de Ven
2006-08-22 19:43 ` Zachary Amsden
2006-08-22 20:16 ` Andi Kleen
2006-08-22 22:02 ` Zachary Amsden
2006-08-23 1:55 ` Rusty Russell
2006-08-23 2:12 ` Zachary Amsden
2006-08-23 7:56 ` Arjan van de Ven
2006-08-23 8:44 ` Zachary Amsden
2006-08-23 8:50 ` Andi Kleen
2006-08-23 9:01 ` Zachary Amsden
2006-08-23 9:06 ` Andi Kleen
2006-08-23 9:14 ` Zachary Amsden
2006-08-23 9:20 ` Andi Kleen
2006-08-23 9:36 ` Zachary Amsden
2006-08-23 9:41 ` Andi Kleen
2006-08-23 9:48 ` Zachary Amsden
2006-08-23 9:50 ` Andi Kleen
2006-08-23 10:03 ` Zachary Amsden
2006-08-23 11:24 ` Andi Kleen
2006-08-23 8:56 ` Arjan van de Ven
2006-08-23 8:18 ` Andi Kleen
2006-08-23 8:38 ` Zachary Amsden
2006-08-22 21:36 ` Alan Cox
2006-08-22 13:45 ` Arjan van de Ven
2006-08-22 13:50 ` Andi Kleen
2006-08-22 14:25 ` Adrian Bunk
2006-08-22 14:54 ` Andi Kleen
2006-08-22 17:36 ` Zachary Amsden
2006-08-22 18:35 ` Alan Cox
2006-08-22 14:59 ` Jeremy Fitzhardinge
2006-08-22 15:12 ` Arjan van de Ven
2006-08-22 15:58 ` Alan Cox
2006-08-23 1:35 ` Rusty Russell
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=200608221544.26989.ak@muc.de \
--to=ak@muc.de \
--cc=akpm@osdl.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=chrisw@sous-sol.org \
--cc=jeremy@goop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=virtualization@lists.osdl.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).