From: Jann Horn <jann-XZ1E9jl8jIdeoWH0uzbU5w@public.gmane.org>
To: Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>
Cc: Kyle Huey <me-OhBmq/TcCDJWk0Htik3J/w@public.gmane.org>,
Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>,
John Stultz <john.stultz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Michal Hocko <mhocko-IBi9RG/b67k@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
"Michael S. Tsirkin"
<mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Alexander Shishkin
<alexander.shishkin-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
Aravind Gopalakrishnan
<Aravind.Gopalakrishnan-5C7GfCeVMHo@public.gmane.org>,
Vlastimil Babka <vbabka-AlSwsSmVLrQ@public.gmane.org>,
"Luis R. Rodriguez"
<mcgrof-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Mateusz Guzik <mguzik-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Alex Thorlton <athorlton-sJ/iWh9BUns@public.gmane.org>,
"Rafael J. Wysocki"
<rafael.j.wysocki-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Dmitry Vyukov <dvyukov-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
Vladimir Zapolskiy
<vladimir_zapolskiy-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>,
Jiri Slaby <jslaby-AlSwsSmVLrQ@public.gmane.org>,
Andrey Ryabinin
<aryabinin-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org>,
Ben Segall <bsegall-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
mainta
Subject: Re: [PATCH] prctl,x86 Add PR_[GET|SET]_CPUID for controlling the CPUID instruction.
Date: Mon, 12 Sep 2016 19:56:56 +0200 [thread overview]
Message-ID: <20160912175656.GA8935@laptop.thejh.net> (raw)
In-Reply-To: <CALCETrVJAib918qn9CL4Tvyfok-8eAHimYDabXUF=1Nsxo4-Pw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Mon, Sep 12, 2016 at 09:56:11AM -0700, Andy Lutomirski wrote:
> On Sep 11, 2016 5:29 PM, "Kyle Huey" <me-OhBmq/TcCDJWk0Htik3J/w@public.gmane.org> wrote:
> >
> > rr (http://rr-project.org/), a userspace record-and-replay reverse-
> > execution debugger, would like to trap and emulate the CPUID instruction.
> > This would allow us to a) mask away certain hardware features that rr does
> > not support (e.g. RDRAND) and b) enable trace portability across machines
> > by providing constant results.
> >
> > Intel supports faulting on the CPUID instruction in newer processors. Bit
> > 31 of MSR_PLATFORM_INFO advertises support for this feature. It is
> > documented in detail in Section 2.3.2 of
> > http://www.intel.com/content/dam/www/public/us/en/documents/application-notes/virtualization-technology-flexmigration-application-note.pdf.
[...]
> If this bit is preserved on fork(), then no_new_privs must be checked
> (or it must be cleared on "unsafe" exec, but that's nasty).
I think you mean "preserved on execve()"?
next prev parent reply other threads:[~2016-09-12 17:56 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-12 0:29 [PATCH] prctl,x86 Add PR_[GET|SET]_CPUID for controlling the CPUID instruction Kyle Huey
[not found] ` <1473640169-24145-1-git-send-email-khuey-OhBmq/TcCDJWk0Htik3J/w@public.gmane.org>
2016-09-12 9:07 ` Borislav Petkov
2016-09-12 14:15 ` Kyle Huey
2016-09-12 14:34 ` Borislav Petkov
2016-09-13 18:42 ` Kyle Huey
2016-09-12 16:56 ` Andy Lutomirski
[not found] ` <CALCETrVJAib918qn9CL4Tvyfok-8eAHimYDabXUF=1Nsxo4-Pw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-09-12 17:18 ` Borislav Petkov
2016-09-12 17:56 ` Jann Horn [this message]
2016-09-12 21:07 ` Andy Lutomirski
2016-09-14 6:13 ` Kyle Huey
[not found] ` <CAP045ApLcQXZP44wry8mofLz2ip1vQbvpnhCjQZsT+JxXmVEzg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-09-14 18:52 ` Andy Lutomirski
2016-09-14 19:22 ` Andrew Cooper
2016-09-14 19:23 ` Boris Ostrovsky
[not found] ` <e7b0b419-ed32-e35b-2f7b-eee71834fafd-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2016-09-14 19:28 ` Andrew Cooper
2016-09-14 19:36 ` Andy Lutomirski
[not found] ` <CALCETrUkmiwLDD0V-b5woDncOzdqZaS4Pg5EnneXD4ZEN7ttbg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-09-14 19:42 ` Andrew Cooper
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