dmaengine: zynqmp_dma: In struct zynqmp_dma_chan fix desc_size data type

[ Upstream commit f9a9f43a62a04ec3183fb0da9226c7706eed0115 ]

In zynqmp_dma_alloc/free_chan_resources functions there is a
potential overflow in the below expressions.

dma_alloc_coherent(chan->dev, (2 * chan->desc_size *
		   ZYNQMP_DMA_NUM_DESCS),
		   &chan->desc_pool_p, GFP_KERNEL);

dma_free_coherent(chan->dev,(2 * ZYNQMP_DMA_DESC_SIZE(chan) *
                 ZYNQMP_DMA_NUM_DESCS),
                chan->desc_pool_v, chan->desc_pool_p);

The arguments desc_size and ZYNQMP_DMA_NUM_DESCS were 32 bit. Though
this overflow condition is not observed but it is a potential problem
in the case of 32-bit multiplication. Hence fix it by changing the
desc_size data type to size_t.

In addition to coverity fix it also reuse ZYNQMP_DMA_DESC_SIZE macro in
dma_alloc_coherent API argument.

Addresses-Coverity: Event overflow_before_widen.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/1652166762-18317-2-git-send-email-radhey.shyam.pandey@xilinx.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
index 97f02f8eb03a864a8f374b135fba877dd4fec282..5257bdbf77fb02d8de12ffef60c806da5cf0e1dd 100644 (file)
--- a/drivers/dma/xilinx/zynqmp_dma.c
+++ b/drivers/dma/xilinx/zynqmp_dma.c
@@ -232,7 +232,7 @@ struct zynqmp_dma_chan {
        bool is_dmacoherent;
        struct tasklet_struct tasklet;
        bool idle;
-       u32 desc_size;
+       size_t desc_size;
        bool err;
        u32 bus_width;
        u32 src_burst_len;
@@ -489,7 +489,8 @@ static int zynqmp_dma_alloc_chan_resources(struct dma_chan *dchan)
        }
 
        chan->desc_pool_v = dma_alloc_coherent(chan->dev,
-                                              (2 * chan->desc_size * ZYNQMP_DMA_NUM_DESCS),
+                                              (2 * ZYNQMP_DMA_DESC_SIZE(chan) *
+                                              ZYNQMP_DMA_NUM_DESCS),
                                               &chan->desc_pool_p, GFP_KERNEL);
        if (!chan->desc_pool_v)
                return -ENOMEM;