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Commit 945a1113 authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds
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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: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a26f5320

mm/page_alloc.c

+9 −15
Original line number Diff line number Diff line
@@ -1923,30 +1923,24 @@ EXPORT_SYMBOL(__alloc_pages_nodemask); 
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)

{

	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)