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authorJulia Lawall <julia@diku.dk>2009-10-17 08:33:47 +0200
committerTakashi Iwai <tiwai@suse.de>2009-10-30 12:01:38 +0100
commite8e0929d7290cab7c5b1a3e5f5f54f73daf38038 (patch)
tree164f1377ab4210212b61ce65fa5b16a0cf82b765
parent4b3be6afa4ab8b3fdce39df68bad71f8b85164de (diff)
ALSA: sound/parisc: Move dereference after NULL test
If the NULL test on h is needed in snd_harmony_mixer_init, then the dereference should be after the NULL test. Actually, there is a sequence of calls: snd_harmony_create, then snd_harmony_pcm_init, and then snd_harmony_mixer_init. snd_harmony_create initializes h, but may indeed leave it as NULL. There was no NULL test at the beginning of snd_harmony_pcm_init, so I have added one. The NULL test in snd_harmony_mixer_init is then not necessary, but in case the ordering of the calls changes, I have left it, and moved the dereference after it. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--sound/parisc/harmony.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/sound/parisc/harmony.c b/sound/parisc/harmony.c
index e924492..f47f9e2 100644
--- a/sound/parisc/harmony.c
+++ b/sound/parisc/harmony.c
@@ -624,6 +624,9 @@ snd_harmony_pcm_init(struct snd_harmony *h)
struct snd_pcm *pcm;
int err;
+ if (snd_BUG_ON(!h))
+ return -EINVAL;
+
harmony_disable_interrupts(h);
err = snd_pcm_new(h->card, "harmony", 0, 1, 1, &pcm);
@@ -865,11 +868,12 @@ snd_harmony_mixer_reset(struct snd_harmony *h)
static int __devinit
snd_harmony_mixer_init(struct snd_harmony *h)
{
- struct snd_card *card = h->card;
+ struct snd_card *card;
int idx, err;
if (snd_BUG_ON(!h))
return -EINVAL;
+ card = h->card;
strcpy(card->mixername, "Harmony Gain control interface");
for (idx = 0; idx < HARMONY_CONTROLS; idx++) {