ARM: 7487/1: mm: avoid setting nG bit for user mappings that aren't present

[pandora-kernel.git] / arch / arm / include / asm / pgtable.h

diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 9451dce..9b419ab 100644 (file)
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -232,6 +232,18 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext)
 #define pte_clear(mm,addr,ptep)        set_pte_ext(ptep, __pte(0), 0)
 
+#define pte_none(pte)          (!pte_val(pte))
+#define pte_present(pte)       (pte_val(pte) & L_PTE_PRESENT)
+#define pte_write(pte)         (!(pte_val(pte) & L_PTE_RDONLY))
+#define pte_dirty(pte)         (pte_val(pte) & L_PTE_DIRTY)
+#define pte_young(pte)         (pte_val(pte) & L_PTE_YOUNG)
+#define pte_exec(pte)          (!(pte_val(pte) & L_PTE_XN))
+#define pte_special(pte)       (0)
+
+#define pte_present_user(pte) \
+       ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \
+        (L_PTE_PRESENT | L_PTE_USER))
+
 #if __LINUX_ARM_ARCH__ < 6
 static inline void __sync_icache_dcache(pte_t pteval)
 {
@@ -243,25 +255,15 @@ extern void __sync_icache_dcache(pte_t pteval);
 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
                              pte_t *ptep, pte_t pteval)
 {
-       if (addr >= TASK_SIZE)
-               set_pte_ext(ptep, pteval, 0);
-       else {
+       unsigned long ext = 0;
+
+       if (addr < TASK_SIZE && pte_present_user(pteval)) {
                __sync_icache_dcache(pteval);
-               set_pte_ext(ptep, pteval, PTE_EXT_NG);
+               ext |= PTE_EXT_NG;
        }
-}
 
-#define pte_none(pte)          (!pte_val(pte))
-#define pte_present(pte)       (pte_val(pte) & L_PTE_PRESENT)
-#define pte_write(pte)         (!(pte_val(pte) & L_PTE_RDONLY))
-#define pte_dirty(pte)         (pte_val(pte) & L_PTE_DIRTY)
-#define pte_young(pte)         (pte_val(pte) & L_PTE_YOUNG)
-#define pte_exec(pte)          (!(pte_val(pte) & L_PTE_XN))
-#define pte_special(pte)       (0)
-
-#define pte_present_user(pte) \
-       ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \
-        (L_PTE_PRESENT | L_PTE_USER))
+       set_pte_ext(ptep, pteval, ext);
+}
 
 #define PTE_BIT_FUNC(fn,op) \
 static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
@@ -288,13 +290,13 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
  *
  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
  *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
- *   <--------------- offset --------------------> <- type --> 0 0 0
+ *   <--------------- offset ----------------------> < type -> 0 0 0
  *
- * This gives us up to 63 swap files and 32GB per swap file.  Note that
+ * This gives us up to 31 swap files and 64GB per swap file.  Note that
  * the offset field is always non-zero.
  */
 #define __SWP_TYPE_SHIFT       3
-#define __SWP_TYPE_BITS                6
+#define __SWP_TYPE_BITS                5
 #define __SWP_TYPE_MASK                ((1 << __SWP_TYPE_BITS) - 1)
 #define __SWP_OFFSET_SHIFT     (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)