[PATCH] swiotlb: Fix uninitialized pointer on DMA ops

[Esteban Zamora]

The mmap function pointer on swiotlb_dma_ops struct is
uninitialized, which causes a random crash when calling
the dma_mmap_coherent function on platforms where no DMA
address translation hardware is available.

Set this pointer to NULL in order to fix the issue.

Signed-off-by: Esteban Zamora <estebanzacr.20@xxxxxxxxx>
---
 kernel/dma/swiotlb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 4f8a6db..9a7718c 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -1082,5 +1082,6 @@ const struct dma_map_ops swiotlb_dma_ops = {
 	.map_page		= swiotlb_map_page,
 	.unmap_page		= swiotlb_unmap_page,
 	.dma_supported		= dma_direct_supported,
+	.mmap                   = NULL,
 };
 EXPORT_SYMBOL(swiotlb_dma_ops);
-- 
2.7.4