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| author | Dave Hansen <dave.hansen@linux.intel.com> | 2016-02-13 00:02:01 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-02-16 12:11:13 +0300 |
| commit | dfb4a70f20c5b3880da56ee4c9484bdb4e8f1e65 (patch) | |
| tree | bf683293576651c11cfbc0062ef202c3d6015d76 /arch/x86/include/asm/cpufeatures.h | |
| parent | 35e97790f5f1e5cf2b5522c55e3e31d5c81bd226 (diff) | |
| download | linux-dfb4a70f20c5b3880da56ee4c9484bdb4e8f1e65.tar.xz | |
x86/cpufeature, x86/mm/pkeys: Add protection keys related CPUID definitions
There are two CPUID bits for protection keys. One is for whether
the CPU contains the feature, and the other will appear set once
the OS enables protection keys. Specifically:
Bit 04: OSPKE. If 1, OS has set CR4.PKE to enable
Protection keys (and the RDPKRU/WRPKRU instructions)
This is because userspace can not see CR4 contents, but it can
see CPUID contents.
X86_FEATURE_PKU is referred to as "PKU" in the hardware documentation:
CPUID.(EAX=07H,ECX=0H):ECX.PKU [bit 3]
X86_FEATURE_OSPKE is "OSPKU":
CPUID.(EAX=07H,ECX=0H):ECX.OSPKE [bit 4]
These are the first CPU features which need to look at the
ECX word in CPUID leaf 0x7, so this patch also includes
fetching that word in to the cpuinfo->x86_capability[] array.
Add it to the disabled-features mask when its config option is
off. Even though we are not using it here, we also extend the
REQUIRED_MASK_BIT_SET() macro to keep it mirroring the
DISABLED_MASK_BIT_SET() version.
This means that in almost all code, you should use:
cpu_has(c, X86_FEATURE_PKU)
and *not* the CONFIG option.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
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@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210201.7714C250@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/cpufeatures.h')
| -rw-r--r-- | arch/x86/include/asm/cpufeatures.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 0ceb6adc8a48..cbb2c568a19e 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -12,7 +12,7 @@ /* * Defines x86 CPU feature bits */ -#define NCAPINTS 16 /* N 32-bit words worth of info */ +#define NCAPINTS 17 /* N 32-bit words worth of info */ #define NBUGINTS 1 /* N 32-bit bug flags */ /* |