[PATCH 1/4] pagewalk: Fix walk_page_range() don't check find_vma()result properly

From: KOSAKI Motohiro
Date: Wed May 25 2011 - 03:09:02 EST


The doc of find_vma() says,

/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
{
(snip)

Thus, caller should confirm whether the returned vma matches a desired one.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
---
mm/pagewalk.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index c3450d5..606bbb4 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -176,7 +176,7 @@ int walk_page_range(unsigned long addr, unsigned long end,
* we can't handled it in the same manner as non-huge pages.
*/
vma = find_vma(walk->mm, addr);
- if (vma && is_vm_hugetlb_page(vma)) {
+ if (vma && vma->vm_start <= addr && is_vm_hugetlb_page(vma)) {
if (vma->vm_end < next)
next = vma->vm_end;
/*
--
1.7.3.1



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