From 602ed87ecd93a857dc687afb938d2c0f45552986 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@suse.cz>
Date: Thu, 29 Mar 2007 01:20:29 -0700
Subject: [PATCH] [PATCH] uml: fix pte bit collision
_PAGE_PROTNONE conflicts with the lowest bit of pgoff. This causes all sorts
of weirdness when nonlinear mappings are used.
Took me a good half day to track this down.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Acked-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/asm-um/pgtable-2level.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/asm-um/pgtable-2level.h b/include/asm-um/pgtable-2level.h
index 6050e0eb257e..172a75fde512 100644
--- a/include/asm-um/pgtable-2level.h
+++ b/include/asm-um/pgtable-2level.h
@@ -45,12 +45,12 @@ static inline void pgd_mkuptodate(pgd_t pgd) { }
((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
/*
- * Bits 0 through 3 are taken
+ * Bits 0 through 4 are taken
*/
-#define PTE_FILE_MAX_BITS 28
+#define PTE_FILE_MAX_BITS 27
-#define pte_to_pgoff(pte) (pte_val(pte) >> 4)
+#define pte_to_pgoff(pte) (pte_val(pte) >> 5)
-#define pgoff_to_pte(off) ((pte_t) { ((off) << 4) + _PAGE_FILE })
+#define pgoff_to_pte(off) ((pte_t) { ((off) << 5) + _PAGE_FILE })
#endif