diff mbox series

[v2,13/23] interconnect: qcom: sm8550: fix registration race

Message ID 20230306075651.2449-14-johan+linaro@kernel.org (mailing list archive)
State New
Headers show
Series interconnect: fix racy provider registration | expand

Commit Message

Johan Hovold March 6, 2023, 7:56 a.m. UTC
The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: e6f0d6a30f73 ("interconnect: qcom: Add SM8550 interconnect provider driver")
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/sm8550.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

Comments

Abel Vesa March 6, 2023, 9:03 a.m. UTC | #1
On 23-03-06 08:56:41, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: e6f0d6a30f73 ("interconnect: qcom: Add SM8550 interconnect provider driver")
> Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---

Any changes since v1 or is it just a resend? 

>  drivers/interconnect/qcom/sm8550.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/sm8550.c b/drivers/interconnect/qcom/sm8550.c
> index 54fa027ab961..7ab492ca8fe0 100644
> --- a/drivers/interconnect/qcom/sm8550.c
> +++ b/drivers/interconnect/qcom/sm8550.c
> @@ -2197,9 +2197,10 @@ static int qnoc_probe(struct platform_device *pdev)
>  	provider->pre_aggregate = qcom_icc_pre_aggregate;
>  	provider->aggregate = qcom_icc_aggregate;
>  	provider->xlate_extended = qcom_icc_xlate_extended;
> -	INIT_LIST_HEAD(&provider->nodes);
>  	provider->data = data;
>  
> +	icc_provider_init(provider);
> +
>  	qp->dev = &pdev->dev;
>  	qp->bcms = desc->bcms;
>  	qp->num_bcms = desc->num_bcms;
> @@ -2208,12 +2209,6 @@ static int qnoc_probe(struct platform_device *pdev)
>  	if (IS_ERR(qp->voter))
>  		return PTR_ERR(qp->voter);
>  
> -	ret = icc_provider_add(provider);
> -	if (ret) {
> -		dev_err_probe(&pdev->dev, ret,
> -			      "error adding interconnect provider\n");
> -		return ret;
> -	}
>  
>  	for (i = 0; i < qp->num_bcms; i++)
>  		qcom_icc_bcm_init(qp->bcms[i], &pdev->dev);
> @@ -2227,7 +2222,7 @@ static int qnoc_probe(struct platform_device *pdev)
>  		node = icc_node_create(qnodes[i]->id);
>  		if (IS_ERR(node)) {
>  			ret = PTR_ERR(node);
> -			goto err;
> +			goto err_remove_nodes;
>  		}
>  
>  		node->name = qnodes[i]->name;
> @@ -2241,12 +2236,17 @@ static int qnoc_probe(struct platform_device *pdev)
>  	}
>  	data->num_nodes = num_nodes;
>  
> +	ret = icc_provider_register(provider);
> +	if (ret)
> +		goto err_remove_nodes;
> +
>  	platform_set_drvdata(pdev, qp);
>  
>  	return 0;
> -err:
> +
> +err_remove_nodes:
>  	icc_nodes_remove(provider);
> -	icc_provider_del(provider);
> +
>  	return ret;
>  }
>  
> @@ -2254,8 +2254,8 @@ static int qnoc_remove(struct platform_device *pdev)
>  {
>  	struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
>  
> +	icc_provider_deregister(&qp->provider);
>  	icc_nodes_remove(&qp->provider);
> -	icc_provider_del(&qp->provider);
>  
>  	return 0;
>  }
> -- 
> 2.39.2
>
Johan Hovold March 6, 2023, 9:34 a.m. UTC | #2
On Mon, Mar 06, 2023 at 11:03:14AM +0200, Abel Vesa wrote:
> On 23-03-06 08:56:41, Johan Hovold wrote:
> > The current interconnect provider registration interface is inherently
> > racy as nodes are not added until the after adding the provider. This
> > can specifically cause racing DT lookups to fail.
> > 
> > Switch to using the new API where the provider is not registered until
> > after it has been fully initialised.
> > 
> > Fixes: e6f0d6a30f73 ("interconnect: qcom: Add SM8550 interconnect provider driver")
> > Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
> > Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > ---
> 
> Any changes since v1 or is it just a resend? 

Please see the cover letter:

	https://lore.kernel.org/lkml/20230306075651.2449-1-johan+linaro@kernel.org/

Only the first patch of the series was updated in v2.

Johan
Abel Vesa March 6, 2023, 9:39 a.m. UTC | #3
On 23-03-06 10:34:34, Johan Hovold wrote:
> On Mon, Mar 06, 2023 at 11:03:14AM +0200, Abel Vesa wrote:
> > On 23-03-06 08:56:41, Johan Hovold wrote:
> > > The current interconnect provider registration interface is inherently
> > > racy as nodes are not added until the after adding the provider. This
> > > can specifically cause racing DT lookups to fail.
> > > 
> > > Switch to using the new API where the provider is not registered until
> > > after it has been fully initialised.
> > > 
> > > Fixes: e6f0d6a30f73 ("interconnect: qcom: Add SM8550 interconnect provider driver")
> > > Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
> > > Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > > ---
> > 
> > Any changes since v1 or is it just a resend? 
> 
> Please see the cover letter:
> 
> 	https://lore.kernel.org/lkml/20230306075651.2449-1-johan+linaro@kernel.org/
> 
> Only the first patch of the series was updated in v2.

Right, my bad. Though I wasn't CC'ed on that as well.

> 
> Johan
Johan Hovold March 6, 2023, 10:04 a.m. UTC | #4
On Mon, Mar 06, 2023 at 11:39:33AM +0200, Abel Vesa wrote:
> On 23-03-06 10:34:34, Johan Hovold wrote:
> > On Mon, Mar 06, 2023 at 11:03:14AM +0200, Abel Vesa wrote:
> > > On 23-03-06 08:56:41, Johan Hovold wrote:
> > > > The current interconnect provider registration interface is inherently
> > > > racy as nodes are not added until the after adding the provider. This
> > > > can specifically cause racing DT lookups to fail.
> > > > 
> > > > Switch to using the new API where the provider is not registered until
> > > > after it has been fully initialised.
> > > > 
> > > > Fixes: e6f0d6a30f73 ("interconnect: qcom: Add SM8550 interconnect provider driver")
> > > > Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
> > > > Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> > > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > > > ---
> > > 
> > > Any changes since v1 or is it just a resend? 
> > 
> > Please see the cover letter:
> > 
> > 	https://lore.kernel.org/lkml/20230306075651.2449-1-johan+linaro@kernel.org/
> > 
> > Only the first patch of the series was updated in v2.
> 
> Right, my bad. Though I wasn't CC'ed on that as well.

Yeah, sorry about that. I copied the CC list from v1 and forgot to make
sure that all reviewers were copied on the cover letter.

Johan
diff mbox series

Patch

diff --git a/drivers/interconnect/qcom/sm8550.c b/drivers/interconnect/qcom/sm8550.c
index 54fa027ab961..7ab492ca8fe0 100644
--- a/drivers/interconnect/qcom/sm8550.c
+++ b/drivers/interconnect/qcom/sm8550.c
@@ -2197,9 +2197,10 @@  static int qnoc_probe(struct platform_device *pdev)
 	provider->pre_aggregate = qcom_icc_pre_aggregate;
 	provider->aggregate = qcom_icc_aggregate;
 	provider->xlate_extended = qcom_icc_xlate_extended;
-	INIT_LIST_HEAD(&provider->nodes);
 	provider->data = data;
 
+	icc_provider_init(provider);
+
 	qp->dev = &pdev->dev;
 	qp->bcms = desc->bcms;
 	qp->num_bcms = desc->num_bcms;
@@ -2208,12 +2209,6 @@  static int qnoc_probe(struct platform_device *pdev)
 	if (IS_ERR(qp->voter))
 		return PTR_ERR(qp->voter);
 
-	ret = icc_provider_add(provider);
-	if (ret) {
-		dev_err_probe(&pdev->dev, ret,
-			      "error adding interconnect provider\n");
-		return ret;
-	}
 
 	for (i = 0; i < qp->num_bcms; i++)
 		qcom_icc_bcm_init(qp->bcms[i], &pdev->dev);
@@ -2227,7 +2222,7 @@  static int qnoc_probe(struct platform_device *pdev)
 		node = icc_node_create(qnodes[i]->id);
 		if (IS_ERR(node)) {
 			ret = PTR_ERR(node);
-			goto err;
+			goto err_remove_nodes;
 		}
 
 		node->name = qnodes[i]->name;
@@ -2241,12 +2236,17 @@  static int qnoc_probe(struct platform_device *pdev)
 	}
 	data->num_nodes = num_nodes;
 
+	ret = icc_provider_register(provider);
+	if (ret)
+		goto err_remove_nodes;
+
 	platform_set_drvdata(pdev, qp);
 
 	return 0;
-err:
+
+err_remove_nodes:
 	icc_nodes_remove(provider);
-	icc_provider_del(provider);
+
 	return ret;
 }
 
@@ -2254,8 +2254,8 @@  static int qnoc_remove(struct platform_device *pdev)
 {
 	struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
 
+	icc_provider_deregister(&qp->provider);
 	icc_nodes_remove(&qp->provider);
-	icc_provider_del(&qp->provider);
 
 	return 0;
 }