[PATCH v3 6/8] rockchip/rga: use 64-bit arithmetic instead of 32-bit

Gustavo A. R. Silva gustavo at embeddedor.com
Tue Feb 6 08:51:18 PST 2018


Cast p to dma_addr_t in order to avoid a potential integer overflow.
This variable is being used in a context that expects an expression
of type dma_addr_t (u64).

The expression p << PAGE_SHIFT is currently being evaluated
using 32-bit arithmetic.

Addresses-Coverity-ID: 1458347 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavo at embeddedor.com>
---
Changes in v2:
 - Update subject and changelog to better reflect the proposed code change.

Changes in v3:
 - Mention the specific Coverity report in the commit message.

 drivers/media/platform/rockchip/rga/rga-buf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/rockchip/rga/rga-buf.c b/drivers/media/platform/rockchip/rga/rga-buf.c
index 49cacc7..a43b57a 100644
--- a/drivers/media/platform/rockchip/rga/rga-buf.c
+++ b/drivers/media/platform/rockchip/rga/rga-buf.c
@@ -140,7 +140,8 @@ void rga_buf_map(struct vb2_buffer *vb)
 		address = sg_phys(sgl);
 
 		for (p = 0; p < len; p++) {
-			dma_addr_t phys = address + (p << PAGE_SHIFT);
+			dma_addr_t phys = address +
+					  ((dma_addr_t)p << PAGE_SHIFT);
 
 			pages[mapped_size + p] = phys;
 		}
-- 
2.7.4




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