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

[Dong Aisheng-B29396]

> -----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.

Regards
Dong Aisheng


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