RE: [PATCH 3/4] sound/soc/mxs/mxs-saif.c: add missing kfree

From: Julia Lawall
Date: Sun Aug 21 2011 - 06:57:39 EST


On Sun, 21 Aug 2011, Dong Aisheng-B29396 wrote:

> > -----Original Message-----
> > From: Julia Lawall [mailto:julia@xxxxxxx]
> > Sent: Saturday, August 20, 2011 11:19 PM
> > To: Wolfram Sang
> > Cc: Liam Girdwood; kernel-janitors@xxxxxxxxxxxxxxx; Mark Brown; Jaroslav
> > Kysela; Takashi Iwai; Dong Aisheng-B29396; alsa-devel@xxxxxxxxxxxxxxxx;
> > linux-kernel@xxxxxxxxxxxxxxx
> > Subject: Re: [PATCH 3/4] sound/soc/mxs/mxs-saif.c: add missing kfree
> >
> > From: Julia Lawall <julia@xxxxxxx>
> >
> > Move the test on pdev->id before the kzalloc to avoid requiring kfree
> > when the test fails. This fix was suggested by Wolfram Sang.
> >
> > A simplified version of the semantic match that finds this problem is as
> > follows: (http://coccinelle.lip6.fr/)
> >
> > // <smpl>
> > @@
> > identifier x;
> > expression E1!=0,E2,E3,E4;
> > statement S;
> > iterator I;
> > @@
> >
> > (
> > if (...) { ... when != kfree(x)
> > when != x = E3
> > when != E3 = x
> > * return ...;
> > }
> > ... when != x = E2
> > when != I(...,x,...) S
> > if (...) { ... when != x = E4
> > kfree(x); ... return ...; }
> > )
> > // </smpl>
> >
> > Signed-off-by: Julia Lawall <julia@xxxxxxx>
> >
> > ---
> > diff --git a/sound/soc/mxs/mxs-saif.c b/sound/soc/mxs/mxs-saif.c index
> > 0b3adae..e9a90e4 100644
> > --- a/sound/soc/mxs/mxs-saif.c
> > +++ b/sound/soc/mxs/mxs-saif.c
> > @@ -519,12 +519,11 @@ static int mxs_saif_probe(struct platform_device
> > *pdev)
> > struct mxs_saif *saif;
> > int ret = 0;
> >
> > + if (pdev->id >= ARRAY_SIZE(mxs_saif))
> > + return -EINVAL;
> > saif = kzalloc(sizeof(*saif), GFP_KERNEL);
> > if (!saif)
> > return -ENOMEM;
> > -
> > - if (pdev->id >= ARRAY_SIZE(mxs_saif))
> > - return -EINVAL;
> > mxs_saif[pdev->id] = saif;
> >
> > saif->clk = clk_get(&pdev->dev, NULL);
>
> Thanks for the finding, Julia.
> It's ok to me.
>
> BTW I guess you may need to resend a new version patch instead of following it
> in this mail thread. :)
> If yes, one minus thing, add one blank line below the line of 'return -ENOMEM'
> may look more comfortable.

OK, I will do both.

Thanks,
julia
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