From: Michal Hocko <mhocko@xxxxxxxx> There is no real reason to blow up just because the caller doesn't know that __get_free_pages cannot return highmem pages. Simply fix that up silently. Even if we have some confused users such a fixup will not be harmful. Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> --- Hi Andrew, previously posted [1] but it fell through cracks. Can we merge it now? [1] http://lkml.kernel.org/r/20171129160446.jluzpv3n6mjc3fwv@xxxxxxxxxxxxxx mm/page_alloc.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 1521100f1e63..5f56f662a52d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4402,18 +4402,14 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid, EXPORT_SYMBOL(__alloc_pages_nodemask); /* - * Common helper functions. + * Common helper functions. Never use with __GFP_HIGHMEM because the returned + * address cannot represent highmem pages. Use alloc_pages and then kmap if + * you need to access high mem. */ unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) { struct page *page; - /* - * __get_free_pages() returns a virtual 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; -- 2.17.1
