Anton Volkov noticed that engine->dev is NULL before
of_dma_controller_register() in probe.
Thus there might be a NULL pointer dereference in
rcar_dmac_chan_start_xfer while accessing chan->chan.device->dev which
is equal to (&dmac->engine)->dev.
To be more safety code, this patch initialize dmac->engine before it.
Reported-by: Anton Volkov <avolkov@xxxxxxxxx>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
---
> Anton, Laurent
I created this patch because noone posted it yesterday.
Anton, you can use this patch and replace Author to you if you want.
Thus, I used [RFC] on this patch
drivers/dma/sh/rcar-dmac.c | 51 +++++++++++++++++++++++-----------------------
1 file changed, 26 insertions(+), 25 deletions(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index ffcadca..6d60628 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -1818,8 +1818,32 @@ static int rcar_dmac_probe(struct platform_device *pdev)
goto error;
}
- /* Initialize the channels. */
- INIT_LIST_HEAD(&dmac->engine.channels);
+ /* Initialize engine */
+ engine = &dmac->engine;
+
+ dma_cap_set(DMA_MEMCPY, engine->cap_mask);
+ dma_cap_set(DMA_SLAVE, engine->cap_mask);
+
+ engine->dev = &pdev->dev;
+ engine->copy_align = ilog2(RCAR_DMAC_MEMCPY_XFER_SIZE);
+
+ engine->src_addr_widths = widths;
+ engine->dst_addr_widths = widths;
+ engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
+ engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+
+ engine->device_alloc_chan_resources = rcar_dmac_alloc_chan_resources;
+ engine->device_free_chan_resources = rcar_dmac_free_chan_resources;
+ engine->device_prep_dma_memcpy = rcar_dmac_prep_dma_memcpy;
+ engine->device_prep_slave_sg = rcar_dmac_prep_slave_sg;
+ engine->device_prep_dma_cyclic = rcar_dmac_prep_dma_cyclic;
+ engine->device_config = rcar_dmac_device_config;
+ engine->device_terminate_all = rcar_dmac_chan_terminate_all;
+ engine->device_tx_status = rcar_dmac_tx_status;
+ engine->device_issue_pending = rcar_dmac_issue_pending;
+ engine->device_synchronize = rcar_dmac_device_synchronize;
+
+ INIT_LIST_HEAD(&engine->channels);
for (i = 0; i < dmac->n_channels; ++i) {
ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i],
@@ -1839,29 +1863,6 @@ static int rcar_dmac_probe(struct platform_device *pdev)
*
* Default transfer size of 32 bytes requires 32-byte alignment.
*/
- engine = &dmac->engine;
- dma_cap_set(DMA_MEMCPY, engine->cap_mask);
- dma_cap_set(DMA_SLAVE, engine->cap_mask);
-
- engine->dev = &pdev->dev;
- engine->copy_align = ilog2(RCAR_DMAC_MEMCPY_XFER_SIZE);
-
- engine->src_addr_widths = widths;
- engine->dst_addr_widths = widths;
- engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
- engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
-
- engine->device_alloc_chan_resources = rcar_dmac_alloc_chan_resources;
- engine->device_free_chan_resources = rcar_dmac_free_chan_resources;
- engine->device_prep_dma_memcpy = rcar_dmac_prep_dma_memcpy;
- engine->device_prep_slave_sg = rcar_dmac_prep_slave_sg;
- engine->device_prep_dma_cyclic = rcar_dmac_prep_dma_cyclic;
- engine->device_config = rcar_dmac_device_config;
- engine->device_terminate_all = rcar_dmac_chan_terminate_all;
- engine->device_tx_status = rcar_dmac_tx_status;
- engine->device_issue_pending = rcar_dmac_issue_pending;
- engine->device_synchronize = rcar_dmac_device_synchronize;
-
ret = dma_async_device_register(engine);
if (ret < 0)
goto error;
--
1.9.1
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