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 <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]> [m68k]
Acked-by: Sam Ravnborg <[email protected]> [sparc]
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index 346ba38..9e52d15 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -404,7 +404,7 @@ static void *s390_dma_alloc(struct device *dev, size_t size,
dma_addr_t map;
size = PAGE_ALIGN(size);
- page = alloc_pages(flag, get_order(size));
+ page = alloc_pages(flag | __GFP_ZERO, get_order(size));
if (!page)
return NULL;
