Fix _PAGE_CHG_MASK so that pte_modify() does not affect the _PAGE_SPECIAL bit.
Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
 /* It should be preserving the high 48 bits and then specifically */
 /* preserving _PAGE_SECONDARY | _PAGE_GROUP_IX */
 #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | \
-                         _PAGE_HPTEFLAGS)
+                         _PAGE_HPTEFLAGS | _PAGE_SPECIAL)
 
 /* Bits to mask out from a PMD to get to the PTE page */
 #define PMD_MASKED_BITS                0
 
  * pgprot changes
  */
 #define _PAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
-                         _PAGE_ACCESSED)
+                         _PAGE_ACCESSED | _PAGE_SPECIAL)
 
 /* Bits to mask out from a PMD to get to the PTE page */
 #define PMD_MASKED_BITS                0x1ff
 
 #define PMD_PAGE_SIZE(pmd)     bad_call_to_PMD_PAGE_SIZE()
 #endif
 
-#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | \
+                        _PAGE_SPECIAL)
 
 
 #define PAGE_PROT_BITS (_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \