thp: fix MADV_DONTNEED vs clear soft dirty race

[sfrench/cifs-2.6.git] / fs / proc / task_mmu.c

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f08bd31c1081cc0536602db9d865f4bf491440c9..312578089544dbd652aac303d0cbabee8fbcb968 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -900,7 +900,14 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma,
 static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
                unsigned long addr, pmd_t *pmdp)
 {
-       pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
+       pmd_t pmd = *pmdp;
+
+       /* See comment in change_huge_pmd() */
+       pmdp_invalidate(vma, addr, pmdp);
+       if (pmd_dirty(*pmdp))
+               pmd = pmd_mkdirty(pmd);
+       if (pmd_young(*pmdp))
+               pmd = pmd_mkyoung(pmd);
 
        pmd = pmd_wrprotect(pmd);
        pmd = pmd_clear_soft_dirty(pmd);