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* [v2] dma: mic_x100_dma: use devm_kzalloc to fix an issue
@ 2018-08-27  5:46 Vinod Koul
  0 siblings, 0 replies; 2+ messages in thread
From: Vinod Koul @ 2018-08-27  5:46 UTC (permalink / raw)
  To: Huang Shijie; +Cc: sudeep.dutt, ashutosh.dixit, dmaengine, linux-kernel

On 22-08-18, 10:40, Huang Shijie wrote:
> The following patch introduced an issue.
>     commit f6206f00d8c5 ("dmaengine: mic_x100_dma: use the new helper to simplify the code")
> 
> This issue is :
> 
> 	kfree(mic_dma_dev)
> 	.....
> 	dma_async_device_unregister(mic_dma_dev->device);
> 
> Free the memory, and use it again.
> 
> So use devm_kzalloc to allocate mic_dma_dev to fix it.
> 
> When the Devres try to release the resources, it will call release at the
> following order:
> 
> 	dma_async_device_unregister(mic_dma_dev->device);
> 	.....
> 	kfree(mic_dma_dev)

After fixing the subsystem name, applied thanks

^ permalink raw reply	[flat|nested] 2+ messages in thread
* [v2] dma: mic_x100_dma: use devm_kzalloc to fix an issue
@ 2018-08-22  2:40 Huang Shijie
  0 siblings, 0 replies; 2+ messages in thread
From: Huang Shijie @ 2018-08-22  2:40 UTC (permalink / raw)
  To: vkoul; +Cc: sudeep.dutt, ashutosh.dixit, dmaengine, linux-kernel,
	Huang Shijie

The following patch introduced an issue.
    commit f6206f00d8c5 ("dmaengine: mic_x100_dma: use the new helper to simplify the code")

This issue is :

	kfree(mic_dma_dev)
	.....
	dma_async_device_unregister(mic_dma_dev->device);

Free the memory, and use it again.

So use devm_kzalloc to allocate mic_dma_dev to fix it.

When the Devres try to release the resources, it will call release at the
following order:

	dma_async_device_unregister(mic_dma_dev->device);
	.....
	kfree(mic_dma_dev)

Fixes: f6206f00d8c5 ("dmaengine: mic_x100_dma: use the new helper to simplify the code")
Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
---
v1 --> v2:
     Change the commit message and title
---
 drivers/dma/mic_x100_dma.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/dma/mic_x100_dma.c b/drivers/dma/mic_x100_dma.c
index b76cb17d879c..adfd316db1a8 100644
--- a/drivers/dma/mic_x100_dma.c
+++ b/drivers/dma/mic_x100_dma.c
@@ -639,7 +639,7 @@ static struct mic_dma_device *mic_dma_dev_reg(struct mbus_device *mbdev,
 	int ret;
 	struct device *dev = &mbdev->dev;
 
-	mic_dma_dev = kzalloc(sizeof(*mic_dma_dev), GFP_KERNEL);
+	mic_dma_dev = devm_kzalloc(dev, sizeof(*mic_dma_dev), GFP_KERNEL);
 	if (!mic_dma_dev) {
 		ret = -ENOMEM;
 		goto alloc_error;
@@ -664,7 +664,6 @@ static struct mic_dma_device *mic_dma_dev_reg(struct mbus_device *mbdev,
 reg_error:
 	mic_dma_uninit(mic_dma_dev);
 init_error:
-	kfree(mic_dma_dev);
 	mic_dma_dev = NULL;
 alloc_error:
 	dev_err(dev, "Error at %s %d ret=%d\n", __func__, __LINE__, ret);
@@ -674,7 +673,6 @@ static struct mic_dma_device *mic_dma_dev_reg(struct mbus_device *mbdev,
 static void mic_dma_dev_unreg(struct mic_dma_device *mic_dma_dev)
 {
 	mic_dma_uninit(mic_dma_dev);
-	kfree(mic_dma_dev);
 }
 
 /* DEBUGFS CODE */

^ permalink raw reply related	[flat|nested] 2+ messages in thread

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2018-08-22  2:40 Huang Shijie

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