From a8fa41ad2f6f7ca08edd1afcf8149ae5a4dcf654 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 24 Feb 2017 14:57:54 -0800 Subject: mm, rmap: check all VMAs that PTE-mapped THP can be part of Current rmap code can miss a VMA that maps PTE-mapped THP if the first suppage of the THP was unmapped from the VMA. We need to walk rmap for the whole range of offsets that THP covers, not only the first one. vma_address() also need to be corrected to check the range instead of the first subpage. Link: http://lkml.kernel.org/r/20170129173858.45174-6-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Acked-by: Hillf Danton Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Johannes Weiner Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Srikar Dronamraju Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/internal.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'mm/internal.h') diff --git a/mm/internal.h b/mm/internal.h index 8ab72f4374e0..ccfc2a2969f4 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -335,12 +335,15 @@ __vma_address(struct page *page, struct vm_area_struct *vma) static inline unsigned long vma_address(struct page *page, struct vm_area_struct *vma) { - unsigned long address = __vma_address(page, vma); + unsigned long start, end; + + start = __vma_address(page, vma); + end = start + PAGE_SIZE * (hpage_nr_pages(page) - 1); /* page should be within @vma mapping range */ - VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma); + VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma); - return address; + return max(start, vma->vm_start); } #else /* !CONFIG_MMU */ -- cgit v1.2.3