From: Thomas Gleixner <tglx@linutronix.de>
To: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linuxfoundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>,
David Woodhouse <dwmw@amazon.co.uk>,
Dave Hansen <dave.hansen@intel.com>,
Will Deacon <will.deacon@arm.com>
Subject: Re: [patch V2 1/2] sysfs/cpu: Add vulnerability folder
Date: Mon, 8 Jan 2018 08:33:43 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.20.1801080832040.2094@nanos> (raw)
In-Reply-To: <20180108072930.GB26761@light.dominikbrodowski.net>
On Mon, 8 Jan 2018, Dominik Brodowski wrote:
> On Sun, Jan 07, 2018 at 10:48:00PM +0100, Thomas Gleixner wrote:
> > As the meltdown/spectre problem affects several CPU architectures, it makes
> > sense to have common way to express whether a system is affected by a
> > particular vulnerability or not. If affected the way to express the
> > mitigation should be common as well.
> >
> > Create /sys/devices/system/cpu/vulnerabilities folder and files for
> > meltdown, spectre_v1 and spectre_v2.
> >
> > Allow architectures to override the show function.
> >
> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> > ---
> > Documentation/ABI/testing/sysfs-devices-system-cpu | 16 +++++++
> > drivers/base/Kconfig | 3 +
> > drivers/base/cpu.c | 48 +++++++++++++++++++++
> > include/linux/cpu.h | 7 +++
> > 4 files changed, 74 insertions(+)
> >
> > --- a/Documentation/ABI/testing/sysfs-devices-system-cpu
> > +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
> > @@ -373,3 +373,19 @@ Contact: Linux kernel mailing list <linu
> > Description: information about CPUs heterogeneity.
> >
> > cpu_capacity: capacity of cpu#.
> > +
> > +What: /sys/devices/system/cpu/vulnerabilities
> > + /sys/devices/system/cpu/vulnerabilities/meltdown
> > + /sys/devices/system/cpu/vulnerabilities/spectre_v1
> > + /sys/devices/system/cpu/vulnerabilities/spectre_v2
> > +Date: Januar 2018
> > +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
> > +Description: Information about CPU vulnerabilities
> > +
> > + The files are named after the code names of CPU
> > + vulnerabilities. The output of those files reflects the
> > + state of the CPUs in the system.
>
> Currently, your code sets X86_BUG_SPECTRE_V[12] unconditionally on x86
> CPUs. However, to my understanding some CPUs which do not execute code
> out-of-order aren't affected. As it is better to err on the safe side for
> now, what about adding a disclaimer at the end of this sentence, such as:
>
> ", but may contain false positives"
We do that in the same way as we did with BUG_INSECURE (now MELTDOWN). Err
out on the safe side and get the exceptions in place when people are
confident about them. It's not going to take long I assume.
Thanks,
tglx
next prev parent reply other threads:[~2018-01-08 7:33 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-07 21:47 [patch V2 0/2] sysfs/cpu: Implement generic vulnerabilites directory Thomas Gleixner
2018-01-07 21:48 ` [patch V2 1/2] sysfs/cpu: Add vulnerability folder Thomas Gleixner
2018-01-07 22:14 ` Konrad Rzeszutek Wilk
2018-01-08 6:53 ` Greg Kroah-Hartman
2018-01-08 7:29 ` Dominik Brodowski
2018-01-08 7:33 ` Thomas Gleixner [this message]
2018-01-08 10:16 ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-01-26 16:23 ` [patch V2 1/2] " Andrea Arcangeli
2018-01-26 16:35 ` Greg Kroah-Hartman
2018-01-29 5:30 ` Jon Masters
2018-01-07 21:48 ` [patch V2 2/2] x86/cpu: Implement CPU vulnerabilites sysfs functions Thomas Gleixner
2018-01-07 22:14 ` Konrad Rzeszutek Wilk
2018-01-08 6:54 ` Greg Kroah-Hartman
2018-01-08 10:17 ` [tip:x86/pti] " tip-bot for Thomas Gleixner
2018-01-07 22:22 [patch V2 1/2] sysfs/cpu: Add vulnerability folder Alexey Dobriyan
2018-01-08 3:50 ` Konrad Rzeszutek Wilk
2018-01-08 5:35 ` Alexey Dobriyan
2018-01-08 9:36 ` Thomas Gleixner
2018-01-08 10:30 ` Alexey Dobriyan
2018-01-08 11:54 ` Alan Cox
2018-01-08 18:04 ` Alexey Dobriyan
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