linux-kernel - Re: Re: Re: [PATCH] rtc: sun6i: Fix memleak in sun6i_rtc_clk

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Date:   Sun, 18 Oct 2020 14:00:41 +0800 (GMT+08:00)
From:   dinghao.liu@....edu.cn
To:     "Alexandre Belloni" <alexandre.belloni@...tlin.com>
Cc:     "Chen-Yu Tsai" <wens@...e.org>, "Kangjie Lu" <kjlu@....edu>,
        linux-rtc@...r.kernel.org,
        "Alessandro Zummo" <a.zummo@...ertech.it>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        "Maxime Ripard" <mripard@...nel.org>,
        linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>
Subject: Re: Re: Re: [PATCH] rtc: sun6i: Fix memleak in sun6i_rtc_clk_init

> On 26/08/2020 16:55:14+0800, dinghao.liu@....edu.cn wrote:
> > > On Sun, Aug 23, 2020 at 3:59 PM Dinghao Liu <dinghao.liu@....edu.cn> wrote:
> > > >
> > > > When clk_hw_register_fixed_rate_with_accuracy() fails,
> > > > clk_data should be freed. It's the same for the subsequent
> > > > error paths.
> > > 
> > > I suppose you should also unregister the already registered clocks
> > > in the latter two error paths?
> > > 
> > 
> > Sounds reasonable. But I find that the existing kernel code takes different
> > strategies for this case. of_sama5d4_sckc_setup() uses clk_hw_unregister() 
> > after clk_hw_register_fixed_rate_with_accuracy(), while _of_fixed_clk_setup()
> > uses clk_hw_unregister_fixed_rate(). But at91sam926x_pmc_setup() just does
> > nothing in this case.
> 
> I guess you should use clk_hw_unregister_fixed_rate after
> clk_hw_register_fixed_rate_with_accuracy. clk_hw_unregister will leak
> the struct clk_fixed_rate. It doesn't matter too much for
> of_sama5d4_sckc_setup and at91sam926x_pmc_setup because if th clock
> can't be registered, the platform will not boot.

Thank you for your advice! I will submit a new patch soon.

Regards,
Dinghao