historical-speck.lore.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Greg KH <gregkh@linuxfoundation.org>
To: speck@linutronix.de
Subject: [MODERATED] Re: [PATCH 0/2] more sampling fun 0
Date: Thu, 20 Feb 2020 09:14:20 +0100	[thread overview]
Message-ID: <20200220081420.GA3328448@kroah.com> (raw)
In-Reply-To: <cover.1582152322.git.mgross@linux.intel.com>

On Wed, Feb 19, 2020 at 02:45:22PM -0800, speck for mark gross wrote:
> From: mark gross <mgross@linux.intel.com>
> Subject: [PATCH 0/2] Special Register Buffer Data Sampling patch set 
> 
> Special Register Buffer Data Sampling is a sampling type of vulnerability that
> leaks data across cores sharing the HW-RNG for vulnerable processors.
> 
> This leak is fixed by a microcode update and is enabled by default.
> 
> This new microcode serializes processor access during execution of RDRAND
> or RDSEED. It ensures that the shared buffer is overwritten before it
> is released for reuse.
> 
> The mitigation impacts the throughput of the RDRAND and RDSEED instructions
> and latency of RT processing running on the socket while executing RDRAND or
> RDSEED.  The micro bechmark of calling RDRAND many times shows a 10x slowdown.

Then we need to stop using RDRAND internally for our "give me a random
number api" which has spread to more and more parts of the kernel.

Here's a patch that does so:
	https://lore.kernel.org/lkml/20200216161836.1976-1-Jason@zx2c4.com/
which I'm going to advise get merged now and backported to the stable
branches.

thanks,

greg k-h

  parent reply	other threads:[~2020-02-20  8:14 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-19 22:45 [MODERATED] [PATCH 0/2] more sampling fun 0 mark gross
2020-02-20  1:53 ` [MODERATED] " mark gross
2020-02-20  8:14 ` Greg KH [this message]
2020-02-20 14:27   ` Greg KH
2020-02-20 15:40     ` mark gross
2020-02-20 16:18       ` Greg KH
2020-02-20 14:55   ` Andi Kleen
2020-02-20 15:05     ` Greg KH
2020-02-20 16:55       ` Andi Kleen
2020-02-20 21:51     ` Josh Poimboeuf
2020-02-20 22:15       ` Andi Kleen
2020-02-20 22:59         ` Kees Cook
2020-02-20 15:09   ` mark gross
2020-02-28 16:21   ` [MODERATED] Additional sampling fun Borislav Petkov
2020-02-28 16:34     ` [MODERATED] " Greg KH
2020-02-28 17:38       ` mark gross
2020-02-28 17:44         ` Thomas Gleixner
2020-02-28 18:09           ` [MODERATED] " Luck, Tony
2020-02-28 18:40             ` Borislav Petkov
2020-02-28 21:53             ` Thomas Gleixner
2020-03-03  1:03               ` [MODERATED] " Luck, Tony

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=20200220081420.GA3328448@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=speck@linutronix.de \
    /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).