From a927cb83f3300bcb1ae18672e58029acddd18b33 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Fri, 12 Feb 2016 13:02:15 -0800 Subject: x86/mm/pkeys: Add functions to fetch PKRU This adds the raw instruction to access PKRU as well as some accessor functions that correctly handle when the CPU does not support the instruction. We don't use it here, but we will use read_pkru() in the next patch. Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner Cc: Andrew Morton 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: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210215.15238D34@viggo.jf.intel.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/pgtable.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/x86/include/asm/pgtable.h') diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 0687c4748b8f..e997dcc6ee2b 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -99,6 +99,14 @@ static inline int pte_dirty(pte_t pte) return pte_flags(pte) & _PAGE_DIRTY; } + +static inline u32 read_pkru(void) +{ + if (boot_cpu_has(X86_FEATURE_OSPKE)) + return __read_pkru(); + return 0; +} + static inline int pte_young(pte_t pte) { return pte_flags(pte) & _PAGE_ACCESSED; -- cgit v1.2.3