[ This is an old patch. I'm working on some new Smatch stuff and I'm
looking at this code, and I don't see how it's possible for this code
to work. I must be missing something and it would help me if someone
could explain to me what's going on so I can fix my software. - dan ]
Hello Peter Hsiang,
The patch dad31ec133ad: "ASoC: Add EQ and filter to max98095 CODEC
driver" from Apr 19, 2011, leads to the following static checker
warning:
sound/soc/codecs/max98095.c:1524 max98095_put_eq_enum()
warn: constraint overflow 'max98095->eq_texts'
required = '(struct max98095_priv)->eq_textcnt'
The error message is saying that Smatch expects we should verify that
the index into the max98095->eq_texts[] array is less than
max98095->eq_textcnt.
sound/soc/codecs/max98095.c
1494 static int max98095_put_eq_enum(struct snd_kcontrol *kcontrol,
1495 struct snd_ctl_elem_value *ucontrol)
1496 {
1497 struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
1498 struct max98095_priv *max98095 = snd_soc_codec_get_drvdata(codec);
1499 struct max98095_pdata *pdata = max98095->pdata;
1500 int channel = max98095_get_eq_channel(kcontrol->id.name);
1501 struct max98095_cdata *cdata;
1502 unsigned int sel = ucontrol->value.enumerated.item[0];
1503 struct max98095_eq_cfg *coef_set;
1504 int fs, best, best_val, i;
1505 int regmask, regsave;
1506
1507 if (WARN_ON(channel > 1))
1508 return -EINVAL;
1509
1510 if (!pdata || !max98095->eq_textcnt)
^^^^^^^^^^^^^^^^^^^^^
Here we check that max98095->eq_textcnt is non-zero.
1511 return 0;
1512
1513 if (sel >= pdata->eq_cfgcnt)
^^^^^^^^^^^^^^^^^^^^^^^
Check here
1514 return -EINVAL;
1515
1516 cdata = &max98095->dai[channel];
1517 cdata->eq_sel = sel;
1518 fs = cdata->rate;
1519
1520 /* Find the selected configuration with nearest sample rate */
1521 best = 0;
1522 best_val = INT_MAX;
1523 for (i = 0; i < pdata->eq_cfgcnt; i++) {
^^^^^^^^^^^^^^^^
According to Smatch the only place where pdata->eq_cfgcnt get set is
from the assignment in max98095_i2c_probe() where we do:
max98095->pdata = i2c->dev.platform_data;
I don't know how i2c->dev.platform_data gets set. I would have thought
it would just be a zeroed buffer.
1524 if (strcmp(pdata->eq_cfg[i].name, max98095->eq_texts[sel]) == 0 &&
^^^^^^^^^^^^^
This is where the warning is generated.
1525 abs(pdata->eq_cfg[i].rate - fs) < best_val) {
1526 best = i;
1527 best_val = abs(pdata->eq_cfg[i].rate - fs);
1528 }
1529 }
regards,
dan carpenter
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
