From dae0a10593007d049ea71601357ac41d4f247ee9 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Mon, 19 Nov 2018 14:45:27 -0800 Subject: [PATCH] x86/cpufeatures, x86/fault: Mark SMAP as disabled when configured out Add X86_FEATURE_SMAP to the disabled features mask as appropriate and use cpu_feature_enabled() in the fault code. This lets us get rid of a redundant IS_ENABLED(CONFIG_X86_SMAP). Signed-off-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Yu-cheng Yu Link: http://lkml.kernel.org/r/fe93332eded3d702f0b0b4cf83928d6830739ba3.1542667307.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/include/asm/disabled-features.h | 8 +++++++- arch/x86/mm/fault.c | 5 +---- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index 33833d1909af..a5ea841cc6d2 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_SMAP +# define DISABLE_SMAP 0 +#else +# define DISABLE_SMAP (1<<(X86_FEATURE_SMAP & 31)) +#endif + #ifdef CONFIG_X86_INTEL_UMIP # define DISABLE_UMIP 0 #else @@ -68,7 +74,7 @@ #define DISABLED_MASK6 0 #define DISABLED_MASK7 (DISABLE_PTI) #define DISABLED_MASK8 0 -#define DISABLED_MASK9 (DISABLE_MPX) +#define DISABLED_MASK9 (DISABLE_MPX|DISABLE_SMAP) #define DISABLED_MASK10 0 #define DISABLED_MASK11 0 #define DISABLED_MASK12 0 diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 8624cb7d8d65..39e39cd42097 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1150,10 +1150,7 @@ static int fault_in_kernel_space(unsigned long address) static inline bool smap_violation(int error_code, struct pt_regs *regs) { - if (!IS_ENABLED(CONFIG_X86_SMAP)) - return false; - - if (!static_cpu_has(X86_FEATURE_SMAP)) + if (!cpu_feature_enabled(X86_FEATURE_SMAP)) return false; if (error_code & X86_PF_USER) -- 2.11.0