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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 <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/fe93332eded3d702f0b0b4cf83928d6830739ba3.1542667307.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Andy Lutomirski 2018-11-19 14:45:27 -08:00 committed by Ingo Molnar
parent 6344be608c
commit dae0a10593
2 changed files with 8 additions and 5 deletions
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8
arch/x86/include/asm/disabled-features.h
View File

@ -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

5
arch/x86/mm/fault.c
View File

@ -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)