mbind: add BUG_ON(!vma) in new_vma_page()

new_vma_page() is called only by page migration called from do_mbind(),
where pages to be migrated are queued into a pagelist by
queue_pages_range().  queue_pages_range() confirms that a queued page
belongs to some vma, so !vma case is not supposed to be happen.  This
patch adds BUG_ON() to catch this unexpected case.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Naoya Horiguchi 2013-09-11 14:22:16 -07:00 committed by Linus Torvalds
parent 9809494578
commit 0bf598d863

View File

@ -1196,12 +1196,14 @@ static struct page *new_vma_page(struct page *page, unsigned long private, int *
break;
vma = vma->vm_next;
}
/*
* queue_pages_range() confirms that @page belongs to some vma,
* so vma shouldn't be NULL.
*/
BUG_ON(!vma);
if (PageHuge(page))
return alloc_huge_page_noerr(vma, address, 1);
/*
* if !vma, alloc_page_vma() will use task or system default policy
*/
return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
}
#else