[PATCH 11/23] interconnect: qcom: msm8974: fix registration race

Johan Hovold posted 23 patches 2 years, 7 months ago
There is a newer version of this series
[PATCH 11/23] interconnect: qcom: msm8974: fix registration race
Posted by Johan Hovold 2 years, 7 months ago
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: 4e60a9568dc6 ("interconnect: qcom: add msm8974 driver")
Cc: stable@vger.kernel.org      # 5.5
Cc: Brian Masney <bmasney@redhat.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/msm8974.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/interconnect/qcom/msm8974.c b/drivers/interconnect/qcom/msm8974.c
index 5ea192f1141d..1828deaca443 100644
--- a/drivers/interconnect/qcom/msm8974.c
+++ b/drivers/interconnect/qcom/msm8974.c
@@ -692,7 +692,6 @@ static int msm8974_icc_probe(struct platform_device *pdev)
 		return ret;
 
 	provider = &qp->provider;
-	INIT_LIST_HEAD(&provider->nodes);
 	provider->dev = dev;
 	provider->set = msm8974_icc_set;
 	provider->aggregate = icc_std_aggregate;
@@ -700,11 +699,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
 	provider->data = data;
 	provider->get_bw = msm8974_get_bw;
 
-	ret = icc_provider_add(provider);
-	if (ret) {
-		dev_err(dev, "error adding interconnect provider: %d\n", ret);
-		goto err_disable_clks;
-	}
+	icc_provider_init(provider);
 
 	for (i = 0; i < num_nodes; i++) {
 		size_t j;
@@ -712,7 +707,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
 		node = icc_node_create(qnodes[i]->id);
 		if (IS_ERR(node)) {
 			ret = PTR_ERR(node);
-			goto err_del_icc;
+			goto err_remove_nodes;
 		}
 
 		node->name = qnodes[i]->name;
@@ -729,15 +724,16 @@ static int msm8974_icc_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_del_icc:
+err_remove_nodes:
 	icc_nodes_remove(provider);
-	icc_provider_del(provider);
-
-err_disable_clks:
 	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
 
 	return ret;
@@ -747,9 +743,9 @@ static int msm8974_icc_remove(struct platform_device *pdev)
 {
 	struct msm8974_icc_provider *qp = platform_get_drvdata(pdev);
 
+	icc_provider_deregister(&qp->provider);
 	icc_nodes_remove(&qp->provider);
 	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
-	icc_provider_del(&qp->provider);
 
 	return 0;
 }
-- 
2.39.1
Re: [PATCH 11/23] interconnect: qcom: msm8974: fix registration race
Posted by Konrad Dybcio 2 years, 7 months ago

On 1.02.2023 11:15, 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: 4e60a9568dc6 ("interconnect: qcom: add msm8974 driver")
> Cc: stable@vger.kernel.org      # 5.5
> Cc: Brian Masney <bmasney@redhat.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/msm8974.c | 20 ++++++++------------
>  1 file changed, 8 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/msm8974.c b/drivers/interconnect/qcom/msm8974.c
> index 5ea192f1141d..1828deaca443 100644
> --- a/drivers/interconnect/qcom/msm8974.c
> +++ b/drivers/interconnect/qcom/msm8974.c
> @@ -692,7 +692,6 @@ static int msm8974_icc_probe(struct platform_device *pdev)
>  		return ret;
>  
>  	provider = &qp->provider;
> -	INIT_LIST_HEAD(&provider->nodes);
>  	provider->dev = dev;
>  	provider->set = msm8974_icc_set;
>  	provider->aggregate = icc_std_aggregate;
> @@ -700,11 +699,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
>  	provider->data = data;
>  	provider->get_bw = msm8974_get_bw;
>  
> -	ret = icc_provider_add(provider);
> -	if (ret) {
> -		dev_err(dev, "error adding interconnect provider: %d\n", ret);
> -		goto err_disable_clks;
> -	}
> +	icc_provider_init(provider);
>  
>  	for (i = 0; i < num_nodes; i++) {
>  		size_t j;
> @@ -712,7 +707,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
>  		node = icc_node_create(qnodes[i]->id);
>  		if (IS_ERR(node)) {
>  			ret = PTR_ERR(node);
> -			goto err_del_icc;
> +			goto err_remove_nodes;
>  		}
>  
>  		node->name = qnodes[i]->name;
> @@ -729,15 +724,16 @@ static int msm8974_icc_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_del_icc:
> +err_remove_nodes:
>  	icc_nodes_remove(provider);
> -	icc_provider_del(provider);
> -
> -err_disable_clks:
>  	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
>  
>  	return ret;
> @@ -747,9 +743,9 @@ static int msm8974_icc_remove(struct platform_device *pdev)
>  {
>  	struct msm8974_icc_provider *qp = platform_get_drvdata(pdev);
>  
> +	icc_provider_deregister(&qp->provider);
>  	icc_nodes_remove(&qp->provider);
>  	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
> -	icc_provider_del(&qp->provider);
>  
>  	return 0;
>  }
Re: [PATCH 11/23] interconnect: qcom: msm8974: fix registration race
Posted by Brian Masney 2 years, 7 months ago
On Wed, Feb 01, 2023 at 11:15:47AM +0100, 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: 4e60a9568dc6 ("interconnect: qcom: add msm8974 driver")
> Cc: stable@vger.kernel.org      # 5.5
> Cc: Brian Masney <bmasney@redhat.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

Reviewed-by: Brian Masney <bmasney@redhat.com>