On 4/29/19 1:25 PM, Ross Zwisler wrote:
Currently in sst_dsp_new() if we get an error return from sst_dma_new()
we just print an error message and then still complete the function
successfully. This means that we are trying to run without sst->dma
properly set up, which will result in NULL pointer dereference when
sst->dma is later used. This was happening for me in
sst_dsp_dma_get_channel():
struct sst_dma *dma = dsp->dma;
...
dma->ch = dma_request_channel(mask, dma_chan_filter, dsp);
This resulted in:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
IP: sst_dsp_dma_get_channel+0x4f/0x125 [snd_soc_sst_firmware]
Fix this by adding proper error handling for the case where we fail to
set up DMA.
This change only affects Haswell and Broadwell systems. Baytrail
systems explicilty opt-out of DMA via sst->pdata->resindex_dma_base
being set to -1.
Signed-off-by: Ross Zwisler <zwis...@google.com>
Cc: sta...@vger.kernel.org
Acked-by: Pierre-Louis Bossart <pierre-louis.boss...@linux.intel.com>
Thanks Ross!
FWIW we should start deprecating this driver now and transition to SOF.
I'll double-check how the upcoming 1.3 release works on my Pixel
2015/Samus device later this week.
---
Changes in v2:
- Upgraded the sst_dma_new() failure message from dev_warn() to dev_err()
(Pierre-Louis).
- Noted in the changelog that this change only affects Haswell and
Broadwell (Pierre-Louis).
---
sound/soc/intel/common/sst-firmware.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/sound/soc/intel/common/sst-firmware.c
b/sound/soc/intel/common/sst-firmware.c
index 1e067504b6043..f830e59f93eaa 100644
--- a/sound/soc/intel/common/sst-firmware.c
+++ b/sound/soc/intel/common/sst-firmware.c
@@ -1251,11 +1251,15 @@ struct sst_dsp *sst_dsp_new(struct device *dev,
goto irq_err;
err = sst_dma_new(sst);
- if (err)
- dev_warn(dev, "sst_dma_new failed %d\n", err);
+ if (err) {
+ dev_err(dev, "sst_dma_new failed %d\n", err);
+ goto dma_err;
+ }
return sst;
+dma_err:
+ free_irq(sst->irq, sst);
irq_err:
if (sst->ops->free)
sst->ops->free(sst);
