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| author | Julia Lawall <julia@diku.dk> | 2009-10-17 08:33:47 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-10-30 12:01:38 +0100 |
| commit | e8e0929d7290cab7c5b1a3e5f5f54f73daf38038 (patch) | |
| tree | 164f1377ab4210212b61ce65fa5b16a0cf82b765 /sound/parisc | |
| parent | 4b3be6afa4ab8b3fdce39df68bad71f8b85164de (diff) | |
| download | lwn-e8e0929d7290cab7c5b1a3e5f5f54f73daf38038.tar.gz lwn-e8e0929d7290cab7c5b1a3e5f5f54f73daf38038.zip | |
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>
Diffstat (limited to 'sound/parisc')
| -rw-r--r-- | sound/parisc/harmony.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/sound/parisc/harmony.c b/sound/parisc/harmony.c index e924492df21d..f47f9e226b08 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++) { |