The patch 3117bb3109dc: "ASoC: fsl_asrc: Add ASRC ASoC CPU DAI and platform drivers" from Jul 29, 2014, leads to the following Smatch complaint:
sound/soc/fsl/fsl_asrc_dma.c:304 fsl_asrc_dma_shutdown() warn: variable dereferenced before check 'pair' (see line 302)
sound/soc/fsl/fsl_asrc_dma.c 301 struct fsl_asrc_pair *pair = runtime->private_data; 302 struct fsl_asrc *asrc_priv = pair->asrc_priv; ^^^^^^^^^^^^^^^ Dereference.
303 304 if (pair && asrc_priv->pair[pair->index] == pair) ^^^^ Check.
305 asrc_priv->pair[pair->index] = NULL; 306
So we just let the driver check pair before using it.
Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Nicolin Chen nicoleotsuka@gmail.com --- sound/soc/fsl/fsl_asrc_dma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c index 5b1e73e..ffc000b 100644 --- a/sound/soc/fsl/fsl_asrc_dma.c +++ b/sound/soc/fsl/fsl_asrc_dma.c @@ -299,9 +299,14 @@ static int fsl_asrc_dma_shutdown(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct fsl_asrc_pair *pair = runtime->private_data; - struct fsl_asrc *asrc_priv = pair->asrc_priv; + struct fsl_asrc *asrc_priv; + + if (!pair) + return 0; + + asrc_priv = pair->asrc_priv;
- if (pair && asrc_priv->pair[pair->index] == pair) + if (asrc_priv->pair[pair->index] == pair) asrc_priv->pair[pair->index] = NULL;
kfree(pair);