mm: add gfp mask checking for __get_free_pages()
__get_free_pages() with __GFP_HIGHMEM is not safe because the return
address cannot represent a highmem page. get_zeroed_page() already has
such a debug checking.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index afda8fd..81926c7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1922,31 +1922,25 @@
*/
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
{
- struct page * page;
+ struct page *page;
+
+ /*
+ * __get_free_pages() returns a 32-bit address, which cannot represent
+ * a highmem page
+ */
+ VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
+
page = alloc_pages(gfp_mask, order);
if (!page)
return 0;
return (unsigned long) page_address(page);
}
-
EXPORT_SYMBOL(__get_free_pages);
unsigned long get_zeroed_page(gfp_t gfp_mask)
{
- struct page * page;
-
- /*
- * get_zeroed_page() returns a 32-bit address, which cannot represent
- * a highmem page
- */
- VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
-
- page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
- if (page)
- return (unsigned long) page_address(page);
- return 0;
+ return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
}
-
EXPORT_SYMBOL(get_zeroed_page);
void __pagevec_free(struct pagevec *pvec)