Re: [PATCH V2] clk: renesas: Fix memory leak of 'cpg'

From: baihaowen
Date: Wed Apr 13 2022 - 05:24:49 EST


在 4/13/22 4:41 PM, Geert Uytterhoeven 写道:
> Hi Haowen,
>
> On Wed, Apr 13, 2022 at 10:30 AM Haowen Bai <baihaowen@xxxxxxxxx> wrote:
>> Fix this issue by freeing the cpg when exiting the function in the
>> error/normal path.
>>
>> Signed-off-by: Haowen Bai <baihaowen@xxxxxxxxx>
> Thanks for your patch!
>
>> --- a/drivers/clk/renesas/clk-r8a73a4.c
>> +++ b/drivers/clk/renesas/clk-r8a73a4.c
>> @@ -215,7 +215,7 @@ static void __init r8a73a4_cpg_clocks_init(struct device_node *np)
>>
>> cpg->reg = of_iomap(np, 0);
>> if (WARN_ON(cpg->reg == NULL))
>> - return;
>> + goto out_free_cpg;
> Note that this is a fatal error, i.e. no chance the system will survive this,
> so cleaning up is moot.
>
>> for (i = 0; i < num_clks; ++i) {
>> const char *name;
>> @@ -233,6 +233,9 @@ static void __init r8a73a4_cpg_clocks_init(struct device_node *np)
>> }
>>
>> of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
>> +out_free_cpg:
>> + kfree(cpg);
>> + kfree(clks);
> Both cpg and clks are still used after returning from this function,
> through the registered clocks and clock provider.
>
>> }
>> CLK_OF_DECLARE(r8a73a4_cpg_clks, "renesas,r8a73a4-cpg-clocks",
>> r8a73a4_cpg_clocks_init);
> NAKed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
Dear Geert Uytterhoeven
Could you show me how and when cpg & clks free ?

--
Haowen Bai