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[PATCH 07/25] x86, pkeys: new page fault error code bit: PF_PK

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From: Dave Hansen <dave.hansen@linux.intel.com>

Note: "PK" is how the Intel SDM refers to this bit, so we also
use that nomenclature.

This only defines the bit, it does not plumb it anywhere to be
handled.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
---

 b/arch/x86/mm/fault.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff -puN arch/x86/mm/fault.c~pkeys-05-pfec arch/x86/mm/fault.c
--- a/arch/x86/mm/fault.c~pkeys-05-pfec	2015-09-28 11:39:44.073097565 -0700
+++ b/arch/x86/mm/fault.c	2015-09-28 11:39:44.076097701 -0700
@@ -33,6 +33,7 @@
  *   bit 2 ==	 0: kernel-mode access	1: user-mode access
  *   bit 3 ==				1: use of reserved bit detected
  *   bit 4 ==				1: fault was an instruction fetch
+ *   bit 5 ==				1: protection keys block access
  */
 enum x86_pf_error_code {
 
@@ -41,6 +42,7 @@ enum x86_pf_error_code {
 	PF_USER		=		1 << 2,
 	PF_RSVD		=		1 << 3,
 	PF_INSTR	=		1 << 4,
+	PF_PK		=		1 << 5,
 };
 
 /*
@@ -916,7 +918,10 @@ static int spurious_fault_check(unsigned
 
 	if ((error_code & PF_INSTR) && !pte_exec(*pte))
 		return 0;
-
+	/*
+	 * Note: We do not do lazy flushing on protection key
+	 * changes, so no spurious fault will ever set PF_PK.
+	 */
 	return 1;
 }
 
_
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Thread

[PATCH 00/25] x86: Memory Protection Keys Dave Hansen <dave@sr71.net> - 2015-09-28 21:30 +0200
  [PATCH 21/25] mm: implement new mprotect_key() system call Dave Hansen <dave@sr71.net> - 2015-09-28 21:30 +0200
    Re: [PATCH 21/25] mm: implement new mprotect_key() system call Michael Ellerman <mpe@ellerman.id.au> - 2015-09-29 08:40 +0200
      Re: [PATCH 21/25] mm: implement new mprotect_key() system call Dave Hansen <dave@sr71.net> - 2015-09-29 16:20 +0200
  [PATCH 07/25] x86, pkeys: new page fault error code bit: PF_PK Dave Hansen <dave@sr71.net> - 2015-09-28 21:30 +0200
    Re: [PATCH 07/25] x86, pkeys: new page fault error code bit: PF_PK Thomas Gleixner <tglx@linutronix.de> - 2015-10-01 14:00 +0200
      Re: [PATCH 07/25] x86, pkeys: new page fault error code bit: PF_PK Dave Hansen <dave@sr71.net> - 2015-10-01 19:20 +0200
  [PATCH 16/25] x86, pkeys: optimize fault handling in access_error() Dave Hansen <dave@sr71.net> - 2015-09-28 21:30 +0200
  [PATCH 13/25] mm: factor out VMA fault permission checking Dave Hansen <dave@sr71.net> - 2015-09-28 21:30 +0200
  [PATCH 08/25] x86, pkeys: store protection in high VMA flags Dave Hansen <dave@sr71.net> - 2015-09-28 21:30 +0200
  [PATCH 06/25] x86, pkeys: PTE bits for storing protection key Dave Hansen <dave@sr71.net> - 2015-09-28 21:30 +0200
  [PATCH 14/25] mm: simplify get_user_pages() PTE bit handling Dave Hansen <dave@sr71.net> - 2015-09-28 21:30 +0200

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