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[tip:mm/pkeys] x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits () for VMA flags

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Commit-ID:  878ba03932d757ce4e954db4defec74a0de0435b
Gitweb:     http://git.kernel.org/tip/878ba03932d757ce4e954db4defec74a0de0435b
Author:     Dave Hansen <dave.hansen@linux.intel.com>
AuthorDate: Fri, 12 Feb 2016 13:02:37 -0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 18 Feb 2016 19:46:32 +0100

x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits() for VMA flags

calc_vm_prot_bits() takes PROT_{READ,WRITE,EXECUTE} bits and
turns them in to the vma->vm_flags/VM_* bits.  We need to do a
similar thing for protection keys.

We take a protection key (4 bits) and encode it in to the 4
VM_PKEY_* bits.

Note: this code is not new.  It was simply a part of the
mprotect_pkey() patch in the past.  I broke it out for use
in the execute-only support.

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/20160212210237.CFB94AD5@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/uapi/asm/mman.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/include/uapi/asm/mman.h b/arch/x86/include/uapi/asm/mman.h
index e8562e0..39bca7f 100644
--- a/arch/x86/include/uapi/asm/mman.h
+++ b/arch/x86/include/uapi/asm/mman.h
@@ -20,6 +20,12 @@
 		((vm_flags) & VM_PKEY_BIT1 ? _PAGE_PKEY_BIT1 : 0) |	\
 		((vm_flags) & VM_PKEY_BIT2 ? _PAGE_PKEY_BIT2 : 0) |	\
 		((vm_flags) & VM_PKEY_BIT3 ? _PAGE_PKEY_BIT3 : 0))
+
+#define arch_calc_vm_prot_bits(prot, key) (		\
+		((key) & 0x1 ? VM_PKEY_BIT0 : 0) |      \
+		((key) & 0x2 ? VM_PKEY_BIT1 : 0) |      \
+		((key) & 0x4 ? VM_PKEY_BIT2 : 0) |      \
+		((key) & 0x8 ? VM_PKEY_BIT3 : 0))
 #endif
 
 #include <asm-generic/mman.h>

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[PATCH 32/33] x86, pkeys: create an x86 arch_calc_vm_prot_bits() for VMA flags Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
  [tip:mm/pkeys] x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits  () for VMA flags tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100

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