From: Dave Hansen <dave.han...@linux.intel.com>
PF_PK means that a memory access violated the protection key
access restrictions. It is unconditionally an access_error()
because the permissions set on the VMA don't matter (the PKRU
value overrides it), and we never "resolve" PK faults (like
how a COW can "resolve write fault).
Signed-off-by: Dave Hansen <dave.han...@linux.intel.com>
Cc: linux-...@vger.kernel.org
Cc: linux-a...@vger.kernel.org
Cc: linux...@kvack.org
Cc: x...@kernel.org
Cc: torva...@linux-foundation.org
Cc: a...@linux-foundation.org
Cc: Arnd Bergmann <a...@arndb.de>
Cc: mgor...@techsingularity.net
Cc: hu...@google.com
Cc: v...@zeniv.linux.org.uk
---
b/arch/x86/mm/fault.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff -puN arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault arch/x86/mm/fault.c
--- a/arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault 2016-07-07
05:46:59.554745699 -0700
+++ b/arch/x86/mm/fault.c 2016-07-07 05:46:59.558745881 -0700
@@ -1112,6 +1112,15 @@ access_error(unsigned long error_code, s
{
/* This is only called for the current mm, so: */
bool foreign = false;
+
+ /*
+ * Read or write was blocked by protection keys. This is
+ * always an unconditional error and can never result in
+ * a follow-up action to resolve the fault, like a COW.
+ */
+ if (error_code & PF_PK)
+ return 1;
+
/*
* Make sure to check the VMA so that we do not perform
* faults just to hit a PF_PK as soon as we fill in a
_
