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Message-Id: <20160129181725.A21D4163@viggo.jf.intel.com>
Date: Fri, 29 Jan 2016 10:17:25 -0800
From: Dave Hansen <dave@...1.net>
To: linux-kernel@...r.kernel.org
Cc: linux-mm@...ck.org, x86@...nel.org, torvalds@...ux-foundation.org,
Dave Hansen <dave@...1.net>, dave.hansen@...ux.intel.com
Subject: [PATCH 30/31] x86, pkeys: create an x86 arch_calc_vm_prot_bits() for VMA flags
From: Dave Hansen <dave.hansen@...ux.intel.com>
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@...ux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
---
b/arch/x86/include/uapi/asm/mman.h | 6 ++++++
1 file changed, 6 insertions(+)
diff -puN arch/x86/include/uapi/asm/mman.h~pkeys-78-arch_calc_vm_prot_bits arch/x86/include/uapi/asm/mman.h
--- a/arch/x86/include/uapi/asm/mman.h~pkeys-78-arch_calc_vm_prot_bits 2016-01-28 15:52:30.134852035 -0800
+++ b/arch/x86/include/uapi/asm/mman.h 2016-01-28 15:52:30.137852173 -0800
@@ -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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