diff options
| author | Jia-Ju Bai <baijiaju1990@163.com> | 2017-06-01 04:13:54 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2017-06-07 12:28:49 -0300 |
| commit | d989dc20c508cd82e2a95ff5d6c4bb091803f1c8 (patch) | |
| tree | 9b54a9d38bf04fd9e3ebe46e3d0525e89efed0e4 | |
| parent | dde32d413447d7f12031d24c7898dd126e5eabe3 (diff) | |
| download | linux-d989dc20c508cd82e2a95ff5d6c4bb091803f1c8.tar.bz2 | |
[media] ivtv: Fix a sleep-in-atomic bug in snd_ivtv_pcm_hw_free
The driver may sleep under a spin lock, and the function call path is:
snd_ivtv_pcm_hw_free (acquire the lock by spin_lock_irqsave)
vfree --> may sleep
To fix it, the "substream->runtime->dma_area" is passed to a temporary
value, and mark it NULL when holding the lock. The memory is freed by
vfree through the temporary value outside the lock holding.
Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
[hans.verkuil@cisco.com: removed unnecessary 'if (dma_area)']
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
| -rw-r--r-- | drivers/media/pci/ivtv/ivtv-alsa-pcm.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/media/pci/ivtv/ivtv-alsa-pcm.c b/drivers/media/pci/ivtv/ivtv-alsa-pcm.c index 807ead20d212..417d03da01f0 100644 --- a/drivers/media/pci/ivtv/ivtv-alsa-pcm.c +++ b/drivers/media/pci/ivtv/ivtv-alsa-pcm.c @@ -262,14 +262,16 @@ static int snd_ivtv_pcm_hw_free(struct snd_pcm_substream *substream) { struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream); unsigned long flags; + unsigned char *dma_area = NULL; spin_lock_irqsave(&itvsc->slock, flags); if (substream->runtime->dma_area) { dprintk("freeing pcm capture region\n"); - vfree(substream->runtime->dma_area); + dma_area = substream->runtime->dma_area; substream->runtime->dma_area = NULL; } spin_unlock_irqrestore(&itvsc->slock, flags); + vfree(dma_area); return 0; } |