Re: [PATCH 1/2] clk: imx: clk-imx8mp: use dev_ managed memory to avoid memory leak in imx8mp_clocks_probe()

[Peng Fan]

On 4/24/2023 5:23 PM, Yuxing Liu wrote:
> Replace of_iomap() and kzalloc() with devm_of_iomap() and devm_kzalloc()
> which can automatically release the related memory when the device
> or driver is disassembled or unloaded to avoid potential memory leak.

What do you mean "disassembled"? The i.MX8MP is an SoC which has Clock
IP built in the device.

Regards,
Peng.

> In this case,iounmap(anatop_base) in line 427,433 are removed
> as manual release is not required.
>
> Fixes: 9c140d992676 ("clk: imx: Add support for i.MX8MP clock driver")
> Signed-off-by: Yuxing Liu <lyx2022@xxxxxxxxxxx>
> Reviewed-by: Dongliang Mu <dzm91@xxxxxxxxxxx>
> ---
> This issue is found by static analysis and remains untested.
> ---
>   drivers/clk/imx/clk-imx8mp.c | 16 ++++++----------
>   1 file changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/clk/imx/clk-imx8mp.c b/drivers/clk/imx/clk-imx8mp.c
> index 3253589851ff..353d58b665f9 100644
> --- a/drivers/clk/imx/clk-imx8mp.c
> +++ b/drivers/clk/imx/clk-imx8mp.c
> @@ -416,23 +416,19 @@ static int imx8mp_clocks_probe(struct platform_device *pdev)
>   	void __iomem *anatop_base, *ccm_base;
>   
>   	np = of_find_compatible_node(NULL, NULL, "fsl,imx8mp-anatop");
> -	anatop_base = of_iomap(np, 0);
> +	anatop_base = devm_of_iomap(dev, np, 0, NULL);
>   	of_node_put(np);
> -	if (WARN_ON(!anatop_base))
> -		return -ENOMEM;
> +	if (WARN_ON(IS_ERR(anatop_base)))
> +		return PTR_ERR(anatop_base);
>   
>   	np = dev->of_node;
>   	ccm_base = devm_platform_ioremap_resource(pdev, 0);
> -	if (WARN_ON(IS_ERR(ccm_base))) {
> -		iounmap(anatop_base);
> +	if (WARN_ON(IS_ERR(ccm_base)))
>   		return PTR_ERR(ccm_base);
> -	}
>   
> -	clk_hw_data = kzalloc(struct_size(clk_hw_data, hws, IMX8MP_CLK_END), GFP_KERNEL);
> -	if (WARN_ON(!clk_hw_data)) {
> -		iounmap(anatop_base);
> +	clk_hw_data = devm_kzalloc(dev, struct_size(clk_hw_data, hws, IMX8MP_CLK_END), GFP_KERNEL);
> +	if (WARN_ON(!clk_hw_data))
>   		return -ENOMEM;
> -	}
>   
>   	clk_hw_data->num = IMX8MP_CLK_END;
>   	hws = clk_hw_data->hws;