[PATCH v7 20/26] x86/cpufeature: Add User-Mode Instruction Prevention definitions

[Borislav Petkov]

On Fri, May 05, 2017 at 11:17:18AM -0700, Ricardo Neri wrote:
> User-Mode Instruction Prevention is a security feature present in new
> Intel processors that, when set, prevents the execution of a subset of
> instructions if such instructions are executed in user mode (CPL > 0).
> Attempting to execute such instructions causes a general protection
> exception.
> 
> The subset of instructions comprises:
> 
>  * SGDT - Store Global Descriptor Table
>  * SIDT - Store Interrupt Descriptor Table
>  * SLDT - Store Local Descriptor Table
>  * SMSW - Store Machine Status Word
>  * STR  - Store Task Register
> 
> This feature is also added to the list of disabled-features to allow
> a cleaner handling of build-time configuration.
> 
> Cc: Andy Lutomirski <luto at kernel.org>
> Cc: Andrew Morton <akpm at linux-foundation.org>
> Cc: H. Peter Anvin <hpa at zytor.com>
> Cc: Borislav Petkov <bp at suse.de>
> Cc: Brian Gerst <brgerst at gmail.com>
> Cc: Chen Yucong <slaoub at gmail.com>
> Cc: Chris Metcalf <cmetcalf at mellanox.com>
> Cc: Dave Hansen <dave.hansen at linux.intel.com>
> Cc: Fenghua Yu <fenghua.yu at intel.com>
> Cc: Huang Rui <ray.huang at amd.com>
> Cc: Jiri Slaby <jslaby at suse.cz>
> Cc: Jonathan Corbet <corbet at lwn.net>
> Cc: Michael S. Tsirkin <mst at redhat.com>
> Cc: Paul Gortmaker <paul.gortmaker at windriver.com>
> Cc: Peter Zijlstra <peterz at infradead.org>
> Cc: Ravi V. Shankar <ravi.v.shankar at intel.com>
> Cc: Shuah Khan <shuah at kernel.org>
> Cc: Vlastimil Babka <vbabka at suse.cz>
> Cc: Tony Luck <tony.luck at intel.com>
> Cc: Paolo Bonzini <pbonzini at redhat.com>
> Cc: Liang Z. Li <liang.z.li at intel.com>
> Cc: Alexandre Julliard <julliard at winehq.org>
> Cc: Stas Sergeev <stsp at list.ru>
> Cc: x86 at kernel.org
> Cc: linux-msdos at vger.kernel.org
> 
> Signed-off-by: Ricardo Neri <ricardo.neri-calderon at linux.intel.com>
> ---
>  arch/x86/include/asm/cpufeatures.h          | 1 +
>  arch/x86/include/asm/disabled-features.h    | 8 +++++++-
>  arch/x86/include/uapi/asm/processor-flags.h | 2 ++
>  3 files changed, 10 insertions(+), 1 deletion(-)

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

-- 
Regards/Gruss,
    Boris.

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