dmaengine: at_hdmac: do exception handling appropriately in at_dma_xlate()

Commit Message

Yu Kuai July 29, 2020, 12:29 p.m. UTC

Do several things for exception handing:

a. check return value of of_find_device_by_node().
b. call put_device() if memory allocation for 'atslave' failed.
c. if dma_request_channel() failed, call put_device() and kfree().

Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding")
Signed-off-by: Yu Kuai <[e-mail]>
---
 drivers/dma/at_hdmac.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

Comments

Vinod Koul Aug. 17, 2020, 5:16 a.m. UTC | #1

On 29-07-20, 20:29, Yu Kuai wrote:
> Do several things for exception handing:
> 
> a. check return value of of_find_device_by_node().
> b. call put_device() if memory allocation for 'atslave' failed.
> c. if dma_request_channel() failed, call put_device() and kfree().

One patch per change please

Patch

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 45bbcd6146fd..a2cf25c6e3b3 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1650,13 +1650,17 @@  static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
 		return NULL;
 
 	dmac_pdev = of_find_device_by_node(dma_spec->np);
+	if (!dmac_pdev)
+		return NULL;
 
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
 	atslave = kmalloc(sizeof(*atslave), GFP_KERNEL);
-	if (!atslave)
+	if (!atslave) {
+		put_device(&dmac_pdev->dev);
 		return NULL;
+	}
 
 	atslave->cfg = ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW;
 	/*
@@ -1685,8 +1689,11 @@  static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
 	atslave->dma_dev = &dmac_pdev->dev;
 
 	chan = dma_request_channel(mask, at_dma_filter, atslave);
-	if (!chan)
+	if (!chan) {
+		put_device(&dmac_pdev->dev);
+		kfree(atslave);
 		return NULL;
+	}
 
 	atchan = to_at_dma_chan(chan);
 	atchan->per_if = dma_spec->args[0] & 0xff;