mm/ksm: handle protnone saved writes when making page write protect
Without this KSM will consider the page write protected, but a numa
fault can later mark the page writable. This can result in memory
corruption.
Link: http://lkml.kernel.org/r/1487498625-10891-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 6265411..f4ca23b1 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -233,6 +233,10 @@ 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
@@ -241,6 +245,10 @@ 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,
