[media] ivtv: Fix a sleep-in-atomic bug in snd_ivtv_pcm_hw_free
authorJia-Ju Bai <baijiaju1990@163.com>
Thu, 1 Jun 2017 07:13:54 +0000 (04:13 -0300)
committerMauro Carvalho Chehab <mchehab@s-opensource.com>
Wed, 7 Jun 2017 15:28:49 +0000 (12:28 -0300)
commitd989dc20c508cd82e2a95ff5d6c4bb091803f1c8
tree9b54a9d38bf04fd9e3ebe46e3d0525e89efed0e4
parentdde32d413447d7f12031d24c7898dd126e5eabe3
[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>
drivers/media/pci/ivtv/ivtv-alsa-pcm.c