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Re: [PATCH v12 5/7] x86/cpufeature: Detect CPUID faulting support

From Borislav Petkov <bp@suse.de>
Newsgroups linux.kernel
Subject Re: [PATCH v12 5/7] x86/cpufeature: Detect CPUID faulting support
Date 2016-11-17 18:10 +0100
Message-ID <sEymd-3v8-1@gated-at.bofh.it> (permalink)
References <sEkjg-2JC-3@gated-at.bofh.it> <sEkjg-2JC-11@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On Wed, Nov 16, 2016 at 06:06:08PM -0800, Kyle Huey wrote:
> Intel supports faulting on the CPUID instruction beginning with Ivy Bridge.
> When enabled, the processor will fault on attempts to execute the CPUID
> instruction with CPL>0. This will allow a ptracer to emulate the CPUID
> instruction.
> 
> Bit 31 of MSR_PLATFORM_INFO advertises support for this feature. It is
> documented in detail in Section 2.3.2 of
> https://bugzilla.kernel.org/attachment.cgi?id=243991
> 
> Detect support for this feature and expose it as X86_FEATURE_CPUID_FAULT.
> 
> Signed-off-by: Kyle Huey <khuey@kylehuey.com>
> ---
>  arch/x86/include/asm/cpufeatures.h |  1 +
>  arch/x86/include/asm/msr-index.h   |  2 ++
>  arch/x86/kernel/cpu/intel.c        | 12 ++++++++++++
>  3 files changed, 15 insertions(+)

Reviewed-by: Borislav Petkov <bp@suse.de>

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
-- 

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Thread

[PATCH v12 0/7] x86/arch_prctl Add ARCH_[GET|SET]_CPUID for controlling the CPUID instruction Kyle Huey <me@kylehuey.com> - 2016-11-17 03:10 +0100
  [PATCH v12 5/7] x86/cpufeature: Detect CPUID faulting support Kyle Huey <me@kylehuey.com> - 2016-11-17 03:10 +0100
    Re: [PATCH v12 5/7] x86/cpufeature: Detect CPUID faulting support Borislav Petkov <bp@suse.de> - 2016-11-17 18:10 +0100
  [PATCH v12 1/7] x86/arch_prctl/64: Use SYSCALL_DEFINE2 to define sys_arch_prctl Kyle Huey <me@kylehuey.com> - 2016-11-17 03:10 +0100
  [PATCH v12 6/7] x86/arch_prctl: Add ARCH_[GET|SET]_CPUID Kyle Huey <me@kylehuey.com> - 2016-11-17 03:10 +0100
    Re: [PATCH v12 6/7] x86/arch_prctl: Add ARCH_[GET|SET]_CPUID Ingo Molnar <mingo@kernel.org> - 2016-11-18 09:20 +0100
      Re: [PATCH v12 6/7] x86/arch_prctl: Add ARCH_[GET|SET]_CPUID Thomas Gleixner <tglx@linutronix.de> - 2016-11-18 10:00 +0100
        Re: [PATCH v12 6/7] x86/arch_prctl: Add ARCH_[GET|SET]_CPUID Ingo Molnar <mingo@kernel.org> - 2016-11-21 09:30 +0100
          Re: [PATCH v12 6/7] x86/arch_prctl: Add ARCH_[GET|SET]_CPUID Andy Lutomirski <luto@amacapital.net> - 2016-11-22 18:30 +0100
      Re: [PATCH v12 6/7] x86/arch_prctl: Add ARCH_[GET|SET]_CPUID Kyle Huey <me@kylehuey.com> - 2016-11-18 17:00 +0100
      Re: [PATCH v12 6/7] x86/arch_prctl: Add ARCH_[GET|SET]_CPUID Andy Lutomirski <luto@amacapital.net> - 2016-11-18 18:40 +0100

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