linux-kernel - Re: [PATCH] sound/pci/mixart/mixart.c: Add missing snd_card

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Message-ID: <s5hljv55j7o.wl%tiwai@suse.de>
Date:	Thu, 27 Nov 2008 15:36:43 +0100
From:	Takashi Iwai <tiwai@...e.de>
To:	Julia Lawall <julia@...u.dk>
Cc:	perex@...ex.cz, alsa-devel@...a-project.org,
	linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] sound/pci/mixart/mixart.c: Add missing snd_card_free

At Thu, 27 Nov 2008 15:01:51 +0100 (CET),
Julia Lawall wrote:
> 
> On Thu, 27 Nov 2008, Takashi Iwai wrote:
> 
> > At Thu, 27 Nov 2008 14:33:30 +0100 (CET),
> > Julia Lawall wrote:
> > > 
> > > Oops, please ignore this patch.  There is a problem, but the modification 
> > > is not correct.
> > 
> > How about the patch below?
> 
> My solution was to move the initialization of mgr->chip[idx] down below 
> the last error return in snd_mixart_create.  I think it depends on what is 
> going to happen to the structure ops.  In your solution, if ops.dev_free 
> is used later on, then the link between mgr and card will be broken, and 
> no one will know to free card.
> 
> There is the same code and the same problem in sound/pci/pcxhr/pcxhr.c
> 
> I attach a proposed patch for both below.

Looks good.  Could you repost with a readable comment?


thanks,

Takashi

> 
> julia
> 
> > Takashi
> > 
> > ---
> > diff --git a/sound/pci/mixart/mixart.c b/sound/pci/mixart/mixart.c
> > index ae7601f..3cccfed 100644
> > --- a/sound/pci/mixart/mixart.c
> > +++ b/sound/pci/mixart/mixart.c
> > @@ -989,6 +989,7 @@ static int snd_mixart_pcm_digital(struct snd_mixart *chip)
> >  
> >  static int snd_mixart_chip_free(struct snd_mixart *chip)
> >  {
> > +	chip->mgr->chip[chip->chip_idx] = NULL;
> >  	kfree(chip);
> >  	return 0;
> >  }
> > --
> > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> > the body of a message to majordomo@...r.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > 
> 
> ---
>  sound/pci/mixart/mixart.c |    4 +++-
>  sound/pci/pcxhr/pcxhr.c   |    4 +++-
>  2 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/pci/mixart/mixart.c b/sound/pci/mixart/mixart.c
> index ae7601f..f23a735 100644
> --- a/sound/pci/mixart/mixart.c
> +++ b/sound/pci/mixart/mixart.c
> @@ -1010,7 +1010,7 @@ static int __devinit snd_mixart_create(struct mixart_mgr *mgr, struct snd_card *
>  		.dev_free = snd_mixart_chip_dev_free,
>  	};
>  
> -	mgr->chip[idx] = chip = kzalloc(sizeof(*chip), GFP_KERNEL);
> +	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
>  	if (! chip) {
>  		snd_printk(KERN_ERR "cannot allocate chip\n");
>  		return -ENOMEM;
> @@ -1025,6 +1025,7 @@ static int __devinit snd_mixart_create(struct mixart_mgr *mgr, struct snd_card *
>  		return err;
>  	}
>  
> +	mgr->chip[idx] = chip;
>  	snd_card_set_dev(card, &mgr->pci->dev);
>  
>  	return 0;
> @@ -1377,6 +1378,7 @@ static int __devinit snd_mixart_probe(struct pci_dev *pci,
>  		sprintf(card->longname, "%s [PCM #%d]", mgr->longname, i);
>  
>  		if ((err = snd_mixart_create(mgr, card, i)) < 0) {
> +			snd_card_free(card);
>  			snd_mixart_free(mgr);
>  			return err;
>  		}
> diff --git a/sound/pci/pcxhr/pcxhr.c b/sound/pci/pcxhr/pcxhr.c
> index 73de6e9..7d2b136 100644
> --- a/sound/pci/pcxhr/pcxhr.c
> +++ b/sound/pci/pcxhr/pcxhr.c
> @@ -1024,7 +1024,7 @@ static int __devinit pcxhr_create(struct pcxhr_mgr *mgr, struct snd_card *card,
>  		.dev_free = pcxhr_chip_dev_free,
>  	};
>  
> -	mgr->chip[idx] = chip = kzalloc(sizeof(*chip), GFP_KERNEL);
> +	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
>  	if (! chip) {
>  		snd_printk(KERN_ERR "cannot allocate chip\n");
>  		return -ENOMEM;
> @@ -1050,6 +1050,7 @@ static int __devinit pcxhr_create(struct pcxhr_mgr *mgr, struct snd_card *card,
>  		return err;
>  	}
>  
> +	mgr->chip[idx] = chip;
>  	snd_card_set_dev(card, &mgr->pci->dev);
>  
>  	return 0;
> @@ -1310,6 +1311,7 @@ static int __devinit pcxhr_probe(struct pci_dev *pci, const struct pci_device_id
>  		sprintf(card->longname, "%s [PCM #%d]", mgr->longname, i);
>  
>  		if ((err = pcxhr_create(mgr, card, i)) < 0) {
> +			snd_card_free(card);
>  			pcxhr_free(mgr);
>  			return err;
>  		}
> 
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