linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@kernel.org>
To: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Pavel Machek <pavel@ucw.cz>, Kees Cook <keescook@chromium.org>,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	kernel list <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@redhat.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	"kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>
Subject: Re: rowhammer protection [was Re: Getting interrupt every million cache misses]
Date: Fri, 28 Oct 2016 11:35:47 +0200	[thread overview]
Message-ID: <20161028093547.GA9291@gmail.com> (raw)
In-Reply-To: <CAOMGZ=HQxkFYhHuF0mDVcwO7m4z34e_PKb6jHGVC3Jwc-mhfXQ@mail.gmail.com>


* Vegard Nossum <vegard.nossum@gmail.com> wrote:

> Would it make sense to sample the counter on context switch, do some
> accounting on a per-task cache miss counter, and slow down just the
> single task(s) with a too high cache miss rate? That way there's no
> global slowdown (which I assume would be the case here). The task's
> slice of CPU would have to be taken into account because otherwise you
> could have multiple cooperating tasks that each escape the limit but
> taken together go above it.

Attackers could work this around by splitting the rowhammer workload between 
multiple threads/processes.

I.e. the problem is that the risk may come from any 'unprivileged user-space 
code', where the rowhammer workload might be spread over multiple threads, 
processes or even users.

Thanks,

	Ingo

  reply	other threads:[~2016-10-28  9:35 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-26 20:54 Getting interrupt every million cache misses Pavel Machek
2016-10-27  8:28 ` Peter Zijlstra
2016-10-27  8:46   ` Pavel Machek
2016-10-27  9:15     ` Peter Zijlstra
2016-10-27  9:11   ` Pavel Machek
2016-10-27  9:33     ` Peter Zijlstra
2016-10-27 20:40       ` Kees Cook
2016-10-27 21:27         ` rowhammer protection [was Re: Getting interrupt every million cache misses] Pavel Machek
2016-10-28  7:07           ` Ingo Molnar
2016-10-28  8:50             ` Pavel Machek
2016-10-28  8:59               ` Ingo Molnar
2016-10-28 11:55                 ` Pavel Machek
2016-10-28  9:04               ` Peter Zijlstra
2016-10-28  9:27                 ` Vegard Nossum
2016-10-28  9:35                   ` Ingo Molnar [this message]
2016-10-28  9:47                     ` Vegard Nossum
2016-10-28  9:53                     ` [kernel-hardening] " Mark Rutland
2016-10-28 11:27                 ` Pavel Machek
2016-10-28  9:51           ` [kernel-hardening] " Mark Rutland
2016-10-28 11:21             ` Pavel Machek
2016-10-28 14:05               ` Mark Rutland
2016-10-28 14:18                 ` Peter Zijlstra
2016-10-28 18:30                   ` Pavel Machek
2016-10-28 18:48                     ` Peter Zijlstra
2016-11-02 18:13                   ` Pavel Machek
2016-10-28 17:27                 ` Pavel Machek
2016-10-29 13:06                   ` Daniel Gruss
2016-10-29 19:42                     ` Pavel Machek
2016-10-29 20:05                       ` Daniel Gruss
2016-10-29 21:05                         ` Pavel Machek
2016-10-29 21:07                           ` Daniel Gruss
2016-10-29 21:45                             ` Pavel Machek
2016-10-29 21:49                               ` Daniel Gruss
2016-10-29 22:01                                 ` Pavel Machek
2016-10-29 22:02                                   ` Daniel Gruss
2016-10-31  8:27                 ` Pavel Machek
2016-10-31 14:47                   ` Mark Rutland
2016-10-31 21:13                     ` Pavel Machek
2016-10-31 22:09                       ` Mark Rutland
2016-11-01  6:33                   ` Ingo Molnar
2016-11-01  7:20                     ` Daniel Micay
2016-11-01  7:53                     ` Daniel Gruss
2016-11-01  8:10                     ` Pavel Machek
2016-11-01  8:13                       ` Daniel Gruss

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=20161028093547.GA9291@gmail.com \
    --to=mingo@kernel.org \
    --cc=acme@redhat.com \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=keescook@chromium.org \
    --cc=kernel-hardening@lists.openwall.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pavel@ucw.cz \
    --cc=peterz@infradead.org \
    --cc=vegard.nossum@gmail.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).