From: ebiederm@xmission.com (Eric W. Biederman)
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>,
Alex Shi <alex.shi@intel.com>,
Jeremy Fitzhardinge <jeremy@goop.org>,
Will Drewry <wad@chromium.org>, Kees Cook <keescook@chromium.org>,
Julien Tinnes <jln@google.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Dan Rosenberg <drosenberg@vsecurity.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>,
Borislav Petkov <borislav.petkov@amd.com>,
Ingo Molnar <mingo@redhat.com>,
kernel-hardening@lists.openwall.com,
Thomas Gleixner <tglx@linutronix.de>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
virtualization@lists.linux-foundation.org,
xen-devel@lists.xensource.com
Subject: Re: [PATCH] x86: make IDT read-only
Date: Tue, 09 Apr 2013 02:45:46 -0700 [thread overview]
Message-ID: <877gkc596d.fsf@xmission.com> (raw)
In-Reply-To: <51634935.9010905@zytor.com> (H. Peter Anvin's message of "Mon, 08 Apr 2013 15:48:21 -0700")
"H. Peter Anvin" <hpa@zytor.com> writes:
> On 04/08/2013 03:43 PM, Kees Cook wrote:
>> This makes the IDT unconditionally read-only. This primarily removes
>> the IDT from being a target for arbitrary memory write attacks. It has
>> an added benefit of also not leaking (via the "sidt" instruction) the
>> kernel base offset, if it has been relocated.
>>
>> Signed-off-by: Kees Cook <keescook@chromium.org>
>> Cc: Eric Northup <digitaleric@google.com>
>
> Also, tglx: does this interfere with your per-cpu IDT efforts?
Given that we don't change any IDT entries why would anyone want a
per-cpu IDT? The cache lines should easily be shared accross all
processors.
Or are there some giant NUMA machines that trigger cache misses when
accessing the IDT and the penalty for pulling the cache line across
the NUMA fabric is prohibitive?
Eric
next prev parent reply other threads:[~2013-04-09 9:45 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-08 22:43 [PATCH] x86: make IDT read-only Kees Cook
2013-04-08 22:47 ` H. Peter Anvin
2013-04-08 22:55 ` Kees Cook
2013-04-08 22:48 ` H. Peter Anvin
2013-04-09 9:23 ` Thomas Gleixner
2013-04-09 9:45 ` Eric W. Biederman [this message]
2013-04-10 9:57 ` Ingo Molnar
2013-04-10 10:40 ` Eric W. Biederman
2013-04-10 16:31 ` Eric Northup
2013-04-10 16:48 ` H. Peter Anvin
[not found] ` <alpine.LFD.2.02.1304091122490.21884@ionos>
2013-04-09 18:22 ` [kernel-hardening] " Kees Cook
2013-04-09 18:26 ` H. Peter Anvin
2013-04-09 18:31 ` Kees Cook
2013-04-09 18:39 ` H. Peter Anvin
2013-04-09 18:46 ` Kees Cook
2013-04-09 18:50 ` H. Peter Anvin
2013-04-09 18:53 ` Kees Cook
2013-04-09 18:54 ` Eric Northup
2013-04-09 18:59 ` H. Peter Anvin
2013-04-10 0:43 ` Readonly GDT H. Peter Anvin
2013-04-10 0:53 ` Steven Rostedt
2013-04-10 0:58 ` H. Peter Anvin
2013-04-10 9:42 ` [Xen-devel] " Jan Beulich
2013-04-10 14:16 ` H. Peter Anvin
2013-04-10 18:28 ` H. Peter Anvin
2013-04-10 9:41 ` [kernel-hardening] Re: [PATCH] x86: make IDT read-only Ingo Molnar
2013-04-10 0:03 ` H. Peter Anvin
2013-04-10 9:52 ` Ingo Molnar
2013-04-08 22:56 ` Maciej W. Rozycki
[not found] ` <alpine.LFD.2.03.1304082350540.25182@linux-mips.org>
2013-04-08 23:00 ` Kees Cook
2013-04-08 23:05 ` Kees Cook
2013-04-08 23:42 ` Maciej W. Rozycki
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=877gkc596d.fsf@xmission.com \
--to=ebiederm@xmission.com \
--cc=alex.shi@intel.com \
--cc=alexander.h.duyck@intel.com \
--cc=borislav.petkov@amd.com \
--cc=drosenberg@vsecurity.com \
--cc=fweisbec@gmail.com \
--cc=hpa@zytor.com \
--cc=jeremy@goop.org \
--cc=jln@google.com \
--cc=keescook@chromium.org \
--cc=kernel-hardening@lists.openwall.com \
--cc=konrad.wilk@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=virtualization@lists.linux-foundation.org \
--cc=wad@chromium.org \
--cc=x86@kernel.org \
--cc=xen-devel@lists.xensource.com \
/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).