[PATCH 1/2] infiniband/mthca: Fix dma_map_sg error check

[Jack Wang]

dma_map_sg return 0 on error, in case of error set
EIO as return code.

Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Leon Romanovsky <leon@xxxxxxxxxx>
Cc: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: "Håkon Bugge" <haakon.bugge@xxxxxxxxxx>
Cc: linux-rdma@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Fixes: 56483ec1b702 ("[PATCH] IB uverbs: add mthca user doorbell record support")
Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/infiniband/hw/mthca/mthca_memfree.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c
index f2734a5c5f26..44fd5fdf64d5 100644
--- a/drivers/infiniband/hw/mthca/mthca_memfree.c
+++ b/drivers/infiniband/hw/mthca/mthca_memfree.c
@@ -189,7 +189,7 @@ struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
 						   chunk->npages,
 						   DMA_BIDIRECTIONAL);
 
-				if (chunk->nsg <= 0)
+				if (!chunk->nsg)
 					goto fail;
 			}
 
@@ -208,7 +208,7 @@ struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
 		chunk->nsg = dma_map_sg(&dev->pdev->dev, chunk->mem,
 					chunk->npages, DMA_BIDIRECTIONAL);
 
-		if (chunk->nsg <= 0)
+		if (!chunk->nsg)
 			goto fail;
 	}
 
@@ -482,8 +482,9 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 
 	ret = dma_map_sg(&dev->pdev->dev, &db_tab->page[i].mem, 1,
 			 DMA_TO_DEVICE);
-	if (ret < 0) {
+	if (!ret) {
 		unpin_user_page(pages[0]);
+		ret = -EIO;
 		goto out;
 	}
 
-- 
2.34.1