path: root/mm/rmap.c
diff options
authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2010-05-11 14:06:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-11 17:33:42 -0700
commitab941e0fff3947b6dcc9c578d918d1bba54a6874 (patch)
tree5157de1b28370136fde227ecbd7fd2d38c15d30a /mm/rmap.c
parent4a6018f7f4f1075c1a5403b5ec0ee7262187b86c (diff)
rmap: remove anon_vma check in page_address_in_vma()
Currently page_address_in_vma() compares vma->anon_vma and page_anon_vma(page) for parameter check, but in 2.6.34 a vma can have multiple anon_vmas with anon_vma_chain, so current check does not work. (For anonymous page shared by multiple processes, some verified (page,vma) pairs return -EFAULT wrongly.) We can go to checking all anon_vmas in the "same_vma" chain, but it needs to meet lock requirement. Instead, we can remove anon_vma check safely because page_address_in_vma() assumes that page and vma are already checked to belong to the identical process. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
1 files changed, 4 insertions, 5 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 07fc9475879..0feeef860a8 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -336,14 +336,13 @@ vma_address(struct page *page, struct vm_area_struct *vma)
* At what user virtual address is page expected in vma?
- * checking that the page matches the vma.
+ * Caller should check the page is actually part of the vma.
unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
- if (PageAnon(page)) {
- if (vma->anon_vma != page_anon_vma(page))
- return -EFAULT;
- } else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) {
+ if (PageAnon(page))
+ ;
+ else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) {
if (!vma->vm_file ||
vma->vm_file->f_mapping != page->mapping)
return -EFAULT;