From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Subject: 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@xxxxxxxxxxxxxxx Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/task_mmu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff -puN fs/proc/task_mmu.c~thp-fix-madv_dontneed-vs-clear-soft-dirty-race fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c~thp-fix-madv_dontneed-vs-clear-soft-dirty-race +++ a/fs/proc/task_mmu.c @@ -900,7 +900,14 @@ static inline void clear_soft_dirty(stru 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); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
