From ef4c962825c08609d8077c00cf73f26fbdc638cc Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 13 Apr 2017 14:56:28 -0700 Subject: thp: fix MADV_DONTNEED vs clear soft dirty race commit 5b7abeae3af8c08c577e599dd0578b9e3ee6687b upstream. 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 Cc: Andrea Arcangeli Cc: Hillf Danton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/proc/task_mmu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index d598b9c809c1..db1a1427c27a 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -803,7 +803,14 @@ 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); -- cgit v1.2.3