Revert "mm/ksm: handle protnone saved writes when making page write protect"

BugLink: http://bugs.launchpad.net/bugs/1674838
This reverts commit c228a1037cd6bd0064472ea282e3730a342d6fca.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 8c8ba48bef0ba88e9744ad0bebc511f1726e02b1..b6f3a8a4b73829e9bc62f6fde9b2d14d2e2f506d 100644 (file)
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -200,10 +200,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
 #define pte_mk_savedwrite pte_mkwrite
 #endif
 
-#ifndef pte_clear_savedwrite
-#define pte_clear_savedwrite pte_wrprotect
-#endif
-
 #ifndef pmd_savedwrite
 #define pmd_savedwrite pmd_write
 #endif
@@ -212,10 +208,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
 #define pmd_mk_savedwrite pmd_mkwrite
 #endif
 
-#ifndef pmd_clear_savedwrite
-#define pmd_clear_savedwrite pmd_wrprotect
-#endif
-
 #ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 static inline void pmdp_set_wrprotect(struct mm_struct *mm,

diff --git a/mm/ksm.c b/mm/ksm.c
index abc05187168a5cebdd2f6d3aca97fbe1c3fc623c..9dd2e58fb6dc93184c5a9dba3347a2b06cc57c42 100644 (file)
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -880,8 +880,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
        if (WARN_ONCE(!pvmw.pte, "Unexpected PMD mapping?"))
                goto out_unlock;
 
-       if (pte_write(*pvmw.pte) || pte_dirty(*pvmw.pte) ||
-           (pte_protnone(*pvmw.pte) && pte_savedwrite(*pvmw.pte))) {
+       if (pte_write(*pvmw.pte) || pte_dirty(*pvmw.pte)) {
                pte_t entry;
 
                swapped = PageSwapCache(page);
@@ -906,11 +905,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
                }
                if (pte_dirty(entry))
                        set_page_dirty(page);
-
-               if (pte_protnone(entry))
-                       entry = pte_mkclean(pte_clear_savedwrite(entry));
-               else
-                       entry = pte_mkclean(pte_wrprotect(entry));
+               entry = pte_mkclean(pte_wrprotect(entry));
                set_pte_at_notify(mm, pvmw.address, pvmw.pte, entry);
        }
        *orig_pte = *pvmw.pte;