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authorFenghua Yu <fenghua.yu@intel.com>2011-05-18 05:44:26 +0400
committerH. Peter Anvin <hpa@linux.intel.com>2011-05-18 07:56:59 +0400
commitd0281a257f370b09c410e466571858b4e12869c9 (patch)
tree87d48822fbbf0325fdd140d1bcd868ad8c230456 /arch/x86/include/asm/cpufeature.h
parent724a92ee45c04cb9d82884a856b03b1e594d9de1 (diff)
downloadlinux-d0281a257f370b09c410e466571858b4e12869c9.tar.xz
x86, cpufeature: Add cpufeature flag for SMEP
Add support for newly documented SMEP (Supervisor Mode Execution Protection) CPU feature flag. SMEP prevents the CPU in kernel-mode to jump to an executable page that has the user flag set in the PTE. This prevents the kernel from executing user-space code accidentally or maliciously, so it for example prevents kernel exploits from jumping to specially prepared user-mode shell code. [ hpa: added better description by Ingo Molnar ] Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> LKML-Reference: <1305683069-25394-2-git-send-email-fenghua.yu@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/include/asm/cpufeature.h')
-rw-r--r--arch/x86/include/asm/cpufeature.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 7f2f7b123293..8808cdb96c3f 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -195,6 +195,7 @@
/* Intel-defined CPU features, CPUID level 0x00000007:0 (ebx), word 9 */
#define X86_FEATURE_FSGSBASE (9*32+ 0) /* {RD/WR}{FS/GS}BASE instructions*/
+#define X86_FEATURE_SMEP (9*32+ 7) /* Supervisor Mode Execution Protection */
#define X86_FEATURE_ERMS (9*32+ 9) /* Enhanced REP MOVSB/STOSB */
#if defined(__KERNEL__) && !defined(__ASSEMBLY__)