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authorRicardo Neri <ricardo.neri-calderon@linux.intel.com>2017-11-05 18:27:51 -0800
committerIngo Molnar <mingo@kernel.org>2017-11-08 11:16:21 +0100
commit3522c2a6a4f341058b8291326a945e2a2d2aaf55 (patch)
tree3e4933190ed9c0ba8b9403e95f89798a8d9be44e
parent9c6c799faeed54b17857c2eed9058a25b8ee3614 (diff)
downloadlinux-3522c2a6a4f341058b8291326a945e2a2d2aaf55.tar.bz2
x86/cpufeature: Add User-Mode Instruction Prevention definitions
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. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.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: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@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: Tony Luck <tony.luck@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: ricardo.neri@intel.com Link: http://lkml.kernel.org/r/1509935277-22138-7-git-send-email-ricardo.neri-calderon@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/include/asm/cpufeatures.h1
-rw-r--r--arch/x86/include/asm/disabled-features.h8
-rw-r--r--arch/x86/include/uapi/asm/processor-flags.h2
3 files changed, 10 insertions, 1 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index cdf5be866863..c0b0e9e8aa66 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -296,6 +296,7 @@
/* Intel-defined CPU features, CPUID level 0x00000007:0 (ECX), word 16 */
#define X86_FEATURE_AVX512VBMI (16*32+ 1) /* AVX512 Vector Bit Manipulation instructions*/
+#define X86_FEATURE_UMIP (16*32+ 2) /* User Mode Instruction Protection */
#define X86_FEATURE_PKU (16*32+ 3) /* Protection Keys for Userspace */
#define X86_FEATURE_OSPKE (16*32+ 4) /* OS Protection Keys Enable */
#define X86_FEATURE_AVX512_VBMI2 (16*32+ 6) /* Additional AVX512 Vector Bit Manipulation Instructions */
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index c10c9128f54e..14d6d5007314 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -16,6 +16,12 @@
# define DISABLE_MPX (1<<(X86_FEATURE_MPX & 31))
#endif
+#ifdef CONFIG_X86_INTEL_UMIP
+# define DISABLE_UMIP 0
+#else
+# define DISABLE_UMIP (1<<(X86_FEATURE_UMIP & 31))
+#endif
+
#ifdef CONFIG_X86_64
# define DISABLE_VME (1<<(X86_FEATURE_VME & 31))
# define DISABLE_K6_MTRR (1<<(X86_FEATURE_K6_MTRR & 31))
@@ -63,7 +69,7 @@
#define DISABLED_MASK13 0
#define DISABLED_MASK14 0
#define DISABLED_MASK15 0
-#define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57)
+#define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP)
#define DISABLED_MASK17 0
#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 18)
diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h
index 53b4ca55ebb6..7e1e730396ae 100644
--- a/arch/x86/include/uapi/asm/processor-flags.h
+++ b/arch/x86/include/uapi/asm/processor-flags.h
@@ -105,6 +105,8 @@
#define X86_CR4_OSFXSR _BITUL(X86_CR4_OSFXSR_BIT)
#define X86_CR4_OSXMMEXCPT_BIT 10 /* enable unmasked SSE exceptions */
#define X86_CR4_OSXMMEXCPT _BITUL(X86_CR4_OSXMMEXCPT_BIT)
+#define X86_CR4_UMIP_BIT 11 /* enable UMIP support */
+#define X86_CR4_UMIP _BITUL(X86_CR4_UMIP_BIT)
#define X86_CR4_LA57_BIT 12 /* enable 5-level page tables */
#define X86_CR4_LA57 _BITUL(X86_CR4_LA57_BIT)
#define X86_CR4_VMXE_BIT 13 /* enable VMX virtualization */