From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> This allows us to use cpu_feature_enabled(X86_FEATURE_MPX) as both a runtime and compile-time check. When CONFIG_X86_INTEL_MPX is disabled, cpu_feature_enabled(X86_FEATURE_MPX) will evaluate at compile-time to 0. If CONFIG_X86_INTEL_MPX=y, then the cpuid flag will be checked at runtime. Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Signed-off-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx> --- b/arch/x86/include/asm/disabled-features.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff -puN arch/x86/include/asm/disabled-features.h~2014-10-14-04_12-x86-mpx-add-MPX-to-disaabled-features arch/x86/include/asm/disabled-features.h --- a/arch/x86/include/asm/disabled-features.h~2014-10-14-04_12-x86-mpx-add-MPX-to-disaabled-features 2014-11-12 08:49:24.951846882 -0800 +++ b/arch/x86/include/asm/disabled-features.h 2014-11-12 08:49:24.954847017 -0800 @@ -10,6 +10,12 @@ * cpu_feature_enabled(). */ +#ifdef CONFIG_X86_INTEL_MPX +# define DISABLE_MPX 0 +#else +# define DISABLE_MPX (1<<(X86_FEATURE_MPX & 31)) +#endif + #ifdef CONFIG_X86_64 # define DISABLE_VME (1<<(X86_FEATURE_VME & 31)) # define DISABLE_K6_MTRR (1<<(X86_FEATURE_K6_MTRR & 31)) @@ -34,6 +40,6 @@ #define DISABLED_MASK6 0 #define DISABLED_MASK7 0 #define DISABLED_MASK8 0 -#define DISABLED_MASK9 0 +#define DISABLED_MASK9 (DISABLE_MPX) #endif /* _ASM_X86_DISABLED_FEATURES_H */ _
