From 69a8ec2d8155b9121ca2990d43f8363b8e2bf550 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 17 Feb 2016 13:11:12 -0800 Subject: [PATCH] thp, dax: do not try to withdraw pgtable from non-anon VMA DAX doesn't deposit pgtables when it maps huge pages: nothing to withdraw. It can lead to crash. Signed-off-by: Kirill A. Shutemov Cc: Dan Williams Cc: Matthew Wilcox Cc: Andrea Arcangeli Cc: Ross Zwisler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 08fc0ba2207e..722546dcfb7e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1700,7 +1700,8 @@ bool move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma, pmd = pmdp_huge_get_and_clear(mm, old_addr, old_pmd); VM_BUG_ON(!pmd_none(*new_pmd)); - if (pmd_move_must_withdraw(new_ptl, old_ptl)) { + if (pmd_move_must_withdraw(new_ptl, old_ptl) && + vma_is_anonymous(vma)) { pgtable_t pgtable; pgtable = pgtable_trans_huge_withdraw(mm, old_pmd); pgtable_trans_huge_deposit(mm, new_pmd, pgtable); -- 2.20.1