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@kernel.org Cc: Andrew Morton akpm@linux-foundation.org Cc: H. Peter Anvin hpa@zytor.com Cc: Borislav Petkov bp@suse.de Cc: Brian Gerst brgerst@gmail.com Cc: Chen Yucong slaoub@gmail.com Cc: Chris Metcalf cmetcalf@mellanox.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Fenghua Yu fenghua.yu@intel.com Cc: Huang Rui ray.huang@amd.com Cc: Jiri Slaby jslaby@suse.cz Cc: Jonathan Corbet corbet@lwn.net Cc: Michael S. Tsirkin mst@redhat.com Cc: Paul Gortmaker paul.gortmaker@windriver.com Cc: Peter Zijlstra peterz@infradead.org Cc: Ravi V. Shankar ravi.v.shankar@intel.com Cc: Shuah Khan shuah@kernel.org Cc: Vlastimil Babka vbabka@suse.cz Cc: Tony Luck tony.luck@intel.com Cc: Paolo Bonzini pbonzini@redhat.com Cc: Liang Z. Li liang.z.li@intel.com Cc: Alexandre Julliard julliard@winehq.org Cc: Stas Sergeev stsp@list.ru Cc: x86@kernel.org Cc: linux-msdos@vger.kernel.org
Signed-off-by: Ricardo Neri ricardo.neri-calderon@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@suse.de