| Date | Sun, 14 Oct 2012 15:37:29 +0100 | From | Ben Hutchings <> | Subject | [ 116/147] mm: hugetlb: fix pgoff computation when unmapping page from vma |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Hillf Danton <dhillf@gmail.com>
commit 0c176d52b0b2619f231b2bbf329b90c028134f58 upstream.
The computation for pgoff is incorrect, at least with
(vma->vm_pgoff >> PAGE_SHIFT)
involved. It is fixed with the available method if HPAGE_SIZE is concerned in page cache lookup.
[akpm@linux-foundation.org: use vma_hugecache_offset() directly, per Michal] Signed-off-by: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michal Hocko <mhocko@suse.cz> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- mm/hugetlb.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2429,8 +2429,7 @@ static int unmap_ref_private(struct mm_s * from page cache lookup which is in HPAGE_SIZE units. */ address = address & huge_page_mask(h); - pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) - + (vma->vm_pgoff >> PAGE_SHIFT); + pgoff = vma_hugecache_offset(h, vma, address); mapping = vma->vm_file->f_dentry->d_inode->i_mapping; /*
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