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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2017-04-13 14:56:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-04-13 18:24:21 -0700
commit5b7abeae3af8c08c577e599dd0578b9e3ee6687b (patch)
treeebbc301c600e4b5ebc3b06e7959ba81117ca4044
parent58ceeb6bec86d9140f9d91d71a710e963523d063 (diff)
thp: fix MADV_DONTNEED vs clear soft dirty race
Yet another instance of the same race. Fix is identical to change_huge_pmd(). See "thp: fix MADV_DONTNEED vs. numa balancing race" for more details. Link: http://lkml.kernel.org/r/20170302151034.27829-5-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/proc/task_mmu.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f08bd31c1081..312578089544 100644
--- 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);