1 files changed, 34 insertions, 0 deletions

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index b77486d152cd..4e02ee2b071e 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -62,6 +62,15 @@ struct mmu_notifier_ops {
                                  unsigned long address);
 
         /*
+         * change_pte is called in cases that pte mapping to page is changed:
+         * for example, when ksm remaps pte to point to a new shared page.
+         */
+        void (*change_pte)(struct mmu_notifier *mn,
+                           struct mm_struct *mm,
+                           unsigned long address,
+                           pte_t pte);
+
+        /*
          * Before this is invoked any secondary MMU is still ok to
          * read/write to the page previously pointed to by the Linux
          * pte because the page hasn't been freed yet and it won't be
@@ -154,6 +163,8 @@ extern void __mmu_notifier_mm_destroy(struct mm_struct *mm);
 extern void __mmu_notifier_release(struct mm_struct *mm);
 extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
                                           unsigned long address);
+extern void __mmu_notifier_change_pte(struct mm_struct *mm,
+                                      unsigned long address, pte_t pte);
 extern void __mmu_notifier_invalidate_page(struct mm_struct *mm,
                                           unsigned long address);
 extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
@@ -175,6 +186,13 @@ static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
         return 0;
 }
 
+static inline void mmu_notifier_change_pte(struct mm_struct *mm,
+                                           unsigned long address, pte_t pte)
+{
+        if (mm_has_notifiers(mm))
+                __mmu_notifier_change_pte(mm, address, pte);
+}
+
 static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
                                           unsigned long address)
 {
@@ -236,6 +254,16 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
         __young;                                                        \
 })
 
+#define set_pte_at_notify(__mm, __address, __ptep, __pte)               \
+({                                                                      \
+        struct mm_struct *___mm = __mm;                                 \
+        unsigned long ___address = __address;                           \
+        pte_t ___pte = __pte;                                           \
+                                                                        \
+        set_pte_at(___mm, ___address, __ptep, ___pte);                  \
+        mmu_notifier_change_pte(___mm, ___address, ___pte);             \
+})
+
 #else /* CONFIG_MMU_NOTIFIER */
 
 static inline void mmu_notifier_release(struct mm_struct *mm)
@@ -248,6 +276,11 @@ static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
         return 0;
 }
 
+static inline void mmu_notifier_change_pte(struct mm_struct *mm,
+                                           unsigned long address, pte_t pte)
+{
+}
+
 static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
                                           unsigned long address)
 {
@@ -273,6 +306,7 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
 
 #define ptep_clear_flush_young_notify ptep_clear_flush_young
 #define ptep_clear_flush_notify ptep_clear_flush
+#define set_pte_at_notify set_pte_at
 
 #endif /* CONFIG_MMU_NOTIFIER */