Messages in this thread Patch in this message | | | Subject | [PATCH 6 of 8] x86: clarify use of _PAGE_CHG_MASK | Date | Fri, 09 May 2008 12:02:44 +0100 | From | Jeremy Fitzhardinge <> |
| |
_PAGE_CHG_MASK is defined as the set of bits not updated by pte_modify(); specifically, the pfn itself, and the Accessed and Dirty bits (which are updated by hardware).
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> --- include/asm-x86/pgtable.h | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -58,6 +58,7 @@ #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | \ _PAGE_DIRTY) +/* Set of bits not changed in pte_modify */ #define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) #define _PAGE_CACHE_MASK (_PAGE_PCD | _PAGE_PWT) @@ -285,11 +286,8 @@ { pteval_t val = pte_val(pte); - /* - * Chop off the NX bit (if present), and add the NX portion of - * the newprot (if present): - */ - val &= _PAGE_CHG_MASK & ~_PAGE_NX; + /* Extract unchanged bits from pte */ + val &= _PAGE_CHG_MASK; val |= pgprot_val(newprot) & __supported_pte_mask; return __pte(val);
| |