RE: [PATCH 1/3] sdhci-s3c: add missing remove function

Marek Szyprowski
2010-07-12T11:05:39Z

Hello,

On Friday, July 09, 2010 11:26 PM Andrew Morton wrote:

> On Wed, 16 Jun 2010 08:49:54 +0200
> Marek Szyprowski <m.szyprowski@samsung.com> wrote:
>
> > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> > Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> > ---
> > drivers/mmc/host/sdhci-s3c.c | 20 ++++++++++++++++++++
> > 1 files changed, 20 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
> > index af21792..ad30f07 100644
> > --- a/drivers/mmc/host/sdhci-s3c.c
> > +++ b/drivers/mmc/host/sdhci-s3c.c
> > @@ -365,6 +365,26 @@ static int __devinit sdhci_s3c_probe(struct
> platform_device *pdev)
> >
> > static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
> > {
> > + struct sdhci_host *host = platform_get_drvdata(pdev);
> > + struct sdhci_s3c *sc = sdhci_priv(host);
> > + int ptr;
> > +
> > + sdhci_remove_host(host, 1);
> > +
> > + for (ptr = 0; ptr < 3; ptr++) {
> > + clk_disable(sc->clk_bus[ptr]);
> > + clk_put(sc->clk_bus[ptr]);
> > + }
> > + clk_disable(sc->clk_io);
> > + clk_put(sc->clk_io);
> > +
> > + iounmap(host->ioaddr);
> > + release_resource(sc->ioarea);
> > + kfree(sc->ioarea);
> > +
> > + sdhci_free_host(host);
> > + platform_set_drvdata(pdev, NULL);
> > +
> > return 0;
> > }
>
> This looks like it fixes a pretty serious omission. What happens if
> the user rmmods this driver on a 2.6.34 kernel?

System will crash sooner or later once the memory with the code of the
s3c-sdhci.ko module is reused for something else. I really have no idea
how the lack of remove function went unnoticed into the mainline code.

> Because I have a suspicion that this fix should be backported into
> 2.6.34.x?

Right, this is really a good idea. This patch applies cleanly onto
v2.6.34 too.

Best regards
--
Marek Szyprowski
Samsung Poland R&D Center