At Sat, 17 Oct 2009 08:33:22 +0200 (CEST), Julia Lawall wrote:

From: Julia Lawall julia@diku.dk

In pcm.c, if the NULL test on pcm is needed, then the dereference should be after the NULL test.

In dummy.c and ali5451.c, the context of the calls to snd_card_dummy_new_mixer and snd_ali_free_voice show that dummy and pvoice, respectively cannot be NULL.

A simplified version of the semantic match that detects this problem is as follows (http://coccinelle.lip6.fr/):

// <smpl> @match exists@ expression x, E; identifier fld; @@

• x->fld ... when != (x = E|&x)
• x == NULL

// </smpl>

Signed-off-by: Julia Lawall julia@diku.dk

Thanks, applied now.

Takashi

---

sound/core/pcm.c | 5 +++-- sound/drivers/dummy.c | 2 -- sound/pci/ali5451/ali5451.c | 2 +-

diff --git a/sound/core/pcm.c b/sound/core/pcm.c index 0c14401..c69c60b 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -953,11 +953,12 @@ static int snd_pcm_dev_register(struct snd_device *device) struct snd_pcm_substream *substream; struct snd_pcm_notify *notify; char str[16];

• struct snd_pcm *pcm = device->device_data;

• struct snd_pcm *pcm; struct device *dev;

• if (snd_BUG_ON(!pcm || !device))

• if (snd_BUG_ON(!device || !device->device_data)) return -ENXIO;
• pcm = device->device_data; mutex_lock(&register_mutex); err = snd_pcm_add(pcm); if (err) {

diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c index 6ba066c..146ef00 100644 --- a/sound/drivers/dummy.c +++ b/sound/drivers/dummy.c @@ -808,8 +808,6 @@ static int __devinit snd_card_dummy_new_mixer(struct snd_dummy *dummy) unsigned int idx; int err;

• if (snd_BUG_ON(!dummy))

• return -EINVAL;
  

  spin_lock_init(&dummy->mixer_lock); strcpy(card->mixername, "Dummy Mixer");

diff --git a/sound/pci/ali5451/ali5451.c b/sound/pci/ali5451/ali5451.c index b458d20..aaf4da6 100644 --- a/sound/pci/ali5451/ali5451.c +++ b/sound/pci/ali5451/ali5451.c @@ -973,7 +973,7 @@ static void snd_ali_free_voice(struct snd_ali * codec, void *private_data;

snd_ali_printk("free_voice: channel=%d\n",pvoice->number);

• if (pvoice == NULL || !pvoice->use)

• if (!pvoice->use) return; snd_ali_clear_voices(codec, pvoice->number, pvoice->number); spin_lock_irq(&codec->voice_alloc);