Re: [PATCH] Revert "ata: ahci_platform: convert kcalloc to devm_kcalloc"

[Mikko Perttunen]

Thanks!

Reviewed-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>

On 17.07.2018 13:49, Corentin Labbe wrote:
> Since ahci_platform_put_resources() use target_pwrs after "devm_" freed
> it, we cannot use devm_kcalloc for allocating target_pwrs.
>
> This reverts commit bd0038b1b4f499d814d8f33a55b1df5ea6cf3b85.
>
> Reported-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
> Signed-off-by: Corentin Labbe <clabbe@xxxxxxxxxxxx>
> ---
>   drivers/ata/libahci_platform.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
> index fe8939e161ea..2ceebaf2ed56 100644
> --- a/drivers/ata/libahci_platform.c
> +++ b/drivers/ata/libahci_platform.c
> @@ -271,6 +271,8 @@ static void ahci_platform_put_resources(struct device *dev, void *res)
>   	for (c = 0; c < hpriv->nports; c++)
>   		if (hpriv->target_pwrs && hpriv->target_pwrs[c])
>   			regulator_put(hpriv->target_pwrs[c]);
> +
> +	kfree(hpriv->target_pwrs);
>   }
>   
>   static int ahci_platform_get_phy(struct ahci_host_priv *hpriv, u32 port,
> @@ -406,7 +408,11 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
>   		rc = -ENOMEM;
>   		goto err_out;
>   	}
> -	hpriv->target_pwrs = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->target_pwrs), GFP_KERNEL);
> +	/*
> +	 * We cannot use devm_ here, since ahci_platform_put_resources() uses
> +	 * target_pwrs after devm_ have freed memory
> +	 */
> +	hpriv->target_pwrs = kcalloc(hpriv->nports, sizeof(*hpriv->target_pwrs), GFP_KERNEL);
>   	if (!hpriv->target_pwrs) {
>   		rc = -ENOMEM;
>   		goto err_out;