linux-kernel - Re: [PATCH] mmc: sdhci-sprd: Fix some resource leaks in the remove function

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Date:   Sun, 20 Dec 2020 10:05:09 +0800
From:   Orson Zhai <orsonzhai@...il.com>
To:     Christophe JAILLET <christophe.jaillet@...adoo.fr>
Cc:     adrian.hunter@...el.com, Ulf Hansson <ulf.hansson@...aro.org>,
        Baolin Wang <baolin.wang7@...il.com>,
        Lyra Zhang <zhang.lyra@...il.com>, linux-mmc@...r.kernel.org,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        kernel-janitors@...r.kernel.org, billows.wu@...soc.com,
        Wu Hongtao <wuht06@...il.com>
Subject: Re: [PATCH] mmc: sdhci-sprd: Fix some resource leaks in the remove function

On Fri, Dec 18, 2020 at 9:46 PM Christophe JAILLET
<christophe.jaillet@...adoo.fr> wrote:
>
> Le 17/12/2020 à 23:55, Orson Zhai a écrit :
> > + cc: Billows
> >
> > Hi Christophe,
> > On Fri, Dec 18, 2020 at 4:50 AM Christophe JAILLET
> > <christophe.jaillet@...adoo.fr> wrote:
> >>
> >> 'sdhci_remove_host()' and 'sdhci_pltfm_free()' should be used in place of
> >> 'mmc_remove_host()' and 'mmc_free_host()'.
> >>
> >> This avoids some resource leaks, is more in line with the error handling
> >> path of the probe function, and is more consistent with other drivers.
> >>
> >> Fixes: fb8bd90f83c4 ("mmc: sdhci-sprd: Add Spreadtrum's initial host controller")
> >> Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
> >> ---
> >> Other adjustment may be needed.
> >> I'm not sure at all of the 0 passed to 'sdhci_remove_host()'. Some drivers
> >> pass 0, some have some more complicated computation.
> >> ---
> >>   drivers/mmc/host/sdhci-sprd.c | 6 +++---
> >>   1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
> >> index f85171edabeb..5dc36efff47f 100644
> >> --- a/drivers/mmc/host/sdhci-sprd.c
> >> +++ b/drivers/mmc/host/sdhci-sprd.c
> >> @@ -708,14 +708,14 @@ static int sdhci_sprd_remove(struct platform_device *pdev)
> >>   {
> >>          struct sdhci_host *host = platform_get_drvdata(pdev);
> >>          struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
> >> -       struct mmc_host *mmc = host->mmc;
> >>
> >> -       mmc_remove_host(mmc);
> >> +       sdhci_remove_host(host, 0);
> >> +
> >>          clk_disable_unprepare(sprd_host->clk_sdio);
> >>          clk_disable_unprepare(sprd_host->clk_enable);
> >>          clk_disable_unprepare(sprd_host->clk_2x_enable);
> >>
> >> -       mmc_free_host(mmc);
> >> +       sdhci_pltfm_free(pdev);
> >
> > I saw a lot of drivers also use mmc_free_host().
> > Do you have patches elsewhere to clean them?
> >
>
> As far as I can see, all drivers that use 'mmc_free_host' also use
> 'mmc_alloc_host'. (based on 5.10.1 and unless error)
>
> The only exception is 'sdhci-sprd.c'.
>
> So no, I don't plan any other clean-up.
>
>
>
> To spot it, I run one of my own cocci script which compare functions
> called in the remove function and in the error handling path of the probe.
>
> So I caught this one because 'mmc_free_host' is used in the porbe and
> 'sdhci_pltfm_free' in the remove function.

Thanks for the clarification.

Acked-by: Orson Zhai <orson.zhai@...il.com>

>
>
> CJ
>
> > Thanks,
> > -Orson
> >
> >>
> >>          return 0;
> >>   }
> >> --
> >> 2.27.0
> >>
> >
>