Re: [PATCH] interconnect: qcom: Annotate struct icc_onecell_data with __counted_by

[Gustavo A. R. Silva]

On 8/17/23 14:42, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct icc_onecell_data.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Andy Gross <agross@xxxxxxxxxx>
> Cc: Bjorn Andersson <andersson@xxxxxxxxxx>
> Cc: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> Cc: Georgi Djakov <djakov@xxxxxxxxxx>
> Cc: linux-arm-msm@xxxxxxxxxxxxxxx
> Cc: linux-pm@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks
--
Gustavo

> ---
>   drivers/interconnect/qcom/icc-rpmh.c  | 3 +--
>   drivers/interconnect/qcom/msm8974.c   | 2 +-
>   drivers/interconnect/qcom/osm-l3.c    | 2 +-
>   include/linux/interconnect-provider.h | 2 +-
>   4 files changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
> index 8053ec8ab01b..b9f27ce3b607 100644
> --- a/drivers/interconnect/qcom/icc-rpmh.c
> +++ b/drivers/interconnect/qcom/icc-rpmh.c
> @@ -185,6 +185,7 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
>   	data = devm_kzalloc(dev, struct_size(data, nodes, num_nodes), GFP_KERNEL);
>   	if (!data)
>   		return -ENOMEM;
> +	data->num_nodes = num_nodes;
>   
>   	provider = &qp->provider;
>   	provider->dev = dev;
> @@ -228,8 +229,6 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
>   		data->nodes[i] = node;
>   	}
>   
> -	data->num_nodes = num_nodes;
> -
>   	ret = icc_provider_register(provider);
>   	if (ret)
>   		goto err_remove_nodes;
> diff --git a/drivers/interconnect/qcom/msm8974.c b/drivers/interconnect/qcom/msm8974.c
> index b85cab2f208f..885ca9d6d4ed 100644
> --- a/drivers/interconnect/qcom/msm8974.c
> +++ b/drivers/interconnect/qcom/msm8974.c
> @@ -675,6 +675,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
>   			    GFP_KERNEL);
>   	if (!data)
>   		return -ENOMEM;
> +	data->num_nodes = num_nodes;
>   
>   	qp->bus_clks = devm_kmemdup(dev, msm8974_icc_bus_clocks,
>   				    sizeof(msm8974_icc_bus_clocks), GFP_KERNEL);
> @@ -721,7 +722,6 @@ static int msm8974_icc_probe(struct platform_device *pdev)
>   
>   		data->nodes[i] = node;
>   	}
> -	data->num_nodes = num_nodes;
>   
>   	ret = icc_provider_register(provider);
>   	if (ret)
> diff --git a/drivers/interconnect/qcom/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c
> index 056ac91225c4..dc321bb86d0b 100644
> --- a/drivers/interconnect/qcom/osm-l3.c
> +++ b/drivers/interconnect/qcom/osm-l3.c
> @@ -232,6 +232,7 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>   	data = devm_kzalloc(&pdev->dev, struct_size(data, nodes, num_nodes), GFP_KERNEL);
>   	if (!data)
>   		return -ENOMEM;
> +	data->num_nodes = num_nodes;
>   
>   	provider = &qp->provider;
>   	provider->dev = &pdev->dev;
> @@ -261,7 +262,6 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>   
>   		data->nodes[i] = node;
>   	}
> -	data->num_nodes = num_nodes;
>   
>   	ret = icc_provider_register(provider);
>   	if (ret)
> diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h
> index e6d8aca6886d..7ba183f221f1 100644
> --- a/include/linux/interconnect-provider.h
> +++ b/include/linux/interconnect-provider.h
> @@ -33,7 +33,7 @@ struct icc_node_data {
>    */
>   struct icc_onecell_data {
>   	unsigned int num_nodes;
> -	struct icc_node *nodes[];
> +	struct icc_node *nodes[] __counted_by(num_nodes);
>   };
>   
>   struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec,