[PATCH] ccp: ccp_dmaengine_unregister release dma channels

[PATCH] ccp: ccp_dmaengine_unregister release dma channels

[Dāvis Mosāns]

ccp_dmaengine_register adds dma_chan->device_node to dma_dev->channels list
but ccp_dmaengine_unregister didn't remove them.
That can cause crashes in various dmaengine methods that tries to use dma_dev->channels

Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>
---
 drivers/crypto/ccp/ccp-dmaengine.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/crypto/ccp/ccp-dmaengine.c b/drivers/crypto/ccp/ccp-dmaengine.c
index d718db224be42..7d4b4ad1db1f3 100644
--- a/drivers/crypto/ccp/ccp-dmaengine.c
+++ b/drivers/crypto/ccp/ccp-dmaengine.c
@@ -632,6 +632,20 @@ static int ccp_terminate_all(struct dma_chan *dma_chan)
 	return 0;
 }
 
+static void ccp_dma_release(struct ccp_device *ccp)
+{
+	struct ccp_dma_chan *chan;
+	struct dma_chan *dma_chan;
+	unsigned int i;
+
+	for (i = 0; i < ccp->cmd_q_count; i++) {
+		chan = ccp->ccp_dma_chan + i;
+		dma_chan = &chan->dma_chan;
+		tasklet_kill(&chan->cleanup_tasklet);
+		list_del_rcu(&dma_chan->device_node);
+	}
+}
+
 int ccp_dmaengine_register(struct ccp_device *ccp)
 {
 	struct ccp_dma_chan *chan;
@@ -736,6 +750,7 @@ int ccp_dmaengine_register(struct ccp_device *ccp)
 	return 0;
 
 err_reg:
+	ccp_dma_release(ccp);
 	kmem_cache_destroy(ccp->dma_desc_cache);
 
 err_cache:
@@ -752,6 +767,7 @@ void ccp_dmaengine_unregister(struct ccp_device *ccp)
 		return;
 
 	dma_async_device_unregister(dma_dev);
+	ccp_dma_release(ccp);
 
 	kmem_cache_destroy(ccp->dma_desc_cache);
 	kmem_cache_destroy(ccp->dma_cmd_cache);
-- 
2.35.1

Re: [PATCH] ccp: ccp_dmaengine_unregister release dma channels

[John Allen]

On Mon, Feb 28, 2022 at 05:15:45AM +0200, Dāvis Mosāns wrote:
> ccp_dmaengine_register adds dma_chan->device_node to dma_dev->channels list
> but ccp_dmaengine_unregister didn't remove them.
> That can cause crashes in various dmaengine methods that tries to use dma_dev->channels
> 
> Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>

Acked-by: John Allen <john.allen@amd.com>

> ---
>  drivers/crypto/ccp/ccp-dmaengine.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/crypto/ccp/ccp-dmaengine.c b/drivers/crypto/ccp/ccp-dmaengine.c
> index d718db224be42..7d4b4ad1db1f3 100644
> --- a/drivers/crypto/ccp/ccp-dmaengine.c
> +++ b/drivers/crypto/ccp/ccp-dmaengine.c
> @@ -632,6 +632,20 @@ static int ccp_terminate_all(struct dma_chan *dma_chan)
>  	return 0;
>  }
>  
> +static void ccp_dma_release(struct ccp_device *ccp)
> +{
> +	struct ccp_dma_chan *chan;
> +	struct dma_chan *dma_chan;
> +	unsigned int i;
> +
> +	for (i = 0; i < ccp->cmd_q_count; i++) {
> +		chan = ccp->ccp_dma_chan + i;
> +		dma_chan = &chan->dma_chan;
> +		tasklet_kill(&chan->cleanup_tasklet);
> +		list_del_rcu(&dma_chan->device_node);
> +	}
> +}
> +
>  int ccp_dmaengine_register(struct ccp_device *ccp)
>  {
>  	struct ccp_dma_chan *chan;
> @@ -736,6 +750,7 @@ int ccp_dmaengine_register(struct ccp_device *ccp)
>  	return 0;
>  
>  err_reg:
> +	ccp_dma_release(ccp);
>  	kmem_cache_destroy(ccp->dma_desc_cache);
>  
>  err_cache:
> @@ -752,6 +767,7 @@ void ccp_dmaengine_unregister(struct ccp_device *ccp)
>  		return;
>  
>  	dma_async_device_unregister(dma_dev);
> +	ccp_dma_release(ccp);
>  
>  	kmem_cache_destroy(ccp->dma_desc_cache);
>  	kmem_cache_destroy(ccp->dma_cmd_cache);
> -- 
> 2.35.1
> 

Re: [PATCH] ccp: ccp_dmaengine_unregister release dma channels

[Herbert Xu]

Dāvis Mosāns <davispuh@gmail.com> wrote:
> ccp_dmaengine_register adds dma_chan->device_node to dma_dev->channels list
> but ccp_dmaengine_unregister didn't remove them.
> That can cause crashes in various dmaengine methods that tries to use dma_dev->channels
> 
> Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>
> ---
> drivers/crypto/ccp/ccp-dmaengine.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt