svn commit: r255611 - head/sys/arm/arm

[Zbigniew Bodek]

Author: zbb
Date: Mon Sep 16 10:34:44 2013
New Revision: 255611
URL: http://svnweb.freebsd.org/changeset/base/255611

Log:
  Write protect base page after superpage demotion so that it may repromote
  
  When clearing the modification status of the superpage, one of the
  base pages produced during demotion should be marked as write disabled.
  The intention is that subsequent write access may repromote.
  In the current implementation this was done wrong as write permission was
  granted instead of forbidden.
  
  Approved by:	cognet (mentor)
  Approved by:	re

Modified:
  head/sys/arm/arm/pmap-v6.c

Modified: head/sys/arm/arm/pmap-v6.c
==============================================================================
--- head/sys/arm/arm/pmap-v6.c	Mon Sep 16 10:06:40 2013	(r255610)
+++ head/sys/arm/arm/pmap-v6.c	Mon Sep 16 10:34:44 2013	(r255611)
@@ -987,7 +987,7 @@ pmap_clearbit(struct vm_page *m, u_int m
 						    ("pmap_clearbit: no PV "
 						    "entry for managed mapping"));
 						pve->pv_flags &= ~PVF_WRITE;
-						*ptep &= ~L2_APX;
+						*ptep |= L2_APX;
 						PTE_SYNC(ptep);
 					}
 				}