dma-mapping: zero memory returned from dma_alloc_*

If we want to map memory from the DMA allocator to userspace it must be
zeroed at allocation time to prevent stale data leaks.   We already do
this on most common architectures, but some architectures don't do this
yet, fix them up, either by passing GFP_ZERO when we use the normal page
allocator or doing a manual memset otherwise.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Sam Ravnborg <sam@ravnborg.org> [sparc]

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index db203ff69ccf..1525ac00fd02 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -33,7 +33,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
 	 */
 	BUG_ON(gfp & __GFP_HIGHMEM);
 
-	page = alloc_pages(gfp, order);
+	page = alloc_pages(gfp | __GFP_ZERO, order);
 	if (!page)
 		return NULL;