Re: [PATCH] sound/pci/mixart/mixart.c: Add missing snd_card_free

From: Julia Lawall
Date: Thu Nov 27 2008 - 08:33:45 EST


Oops, please ignore this patch. There is a problem, but the modification
is not correct.

julia


On Thu, 27 Nov 2008, Julia Lawall wrote:

> From: Julia Lawall <julia@xxxxxxx>
>
> The function snd_mixart_create creates a link between mgr and card that
> allows snd_mixart_free to free card as well. But if snd_mixart_create
> fails, then the link has not been created and card has to be freed explicitly.
>
>
> The semantic match that finds the problem is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
>
> // <smpl>
> @r exists@
> local idexpression x;
> statement S,S1;
> position p1,p2,p3;
> expression E,E1;
> type T,T1;
> expression *ptr != NULL;
> @@
>
> (
> if ((x@p1 = snd_card_new(...)) == NULL) S
> |
> x@p1 = snd_card_new(...);
> )
> ... when != snd_card_free(...,(T)x,...)
> when != if (...) { <+... snd_card_free(...,(T)x,...) ...+> }
> when != true x == NULL || ...
> when != x = E
> when != E = (T)x
> when any
> (
> if (x == NULL || ...) S1
> |
> if@p2 (...) {
> ... when != snd_card_free(...,(T1)x,...)
> when != if (...) { <+... snd_card_free(...,(T1)x,...) ...+> }
> when != x = E1
> when != E1 = (T1)x
> (
> return \(0\|<+...x...+>\|ptr\);
> |
> return@p3 ...;
> )
> }
> )
>
> @ script:python @
> p1 << r.p1;
> p3 << r.p3;
> @@
>
> print "* file: %s snd_card_new: %s return: %s" % (p1[0].file,p1[0].line,p3[0].line)
>
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@xxxxxxx>
>
> ---
> sound/pci/mixart/mixart.c | 1 +
> 1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/sound/pci/mixart/mixart.c b/sound/pci/mixart/mixart.c
> index ae7601f..1dd90f0 100644
> --- a/sound/pci/mixart/mixart.c
> +++ b/sound/pci/mixart/mixart.c
> @@ -1377,6 +1377,7 @@ 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;
> }
>
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