Re: [PATCH 2/3] echoaudio: Prevent races in calls to set_audio_format()

On Tue, 16 Jun 2020 15:17:42 +0200, Mark Hills wrote:

The function uses chip->comm_page which needs locking against other use at the same time.

Signed-off-by: Mark Hills mark@xwax.org

sound/pci/echoaudio/echoaudio.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/sound/pci/echoaudio/echoaudio.c b/sound/pci/echoaudio/echoaudio.c index 82a49dfd2384..8cf08988959f 100644 --- a/sound/pci/echoaudio/echoaudio.c +++ b/sound/pci/echoaudio/echoaudio.c @@ -711,9 +711,22 @@ static int pcm_prepare(struct snd_pcm_substream *substream)

if (snd_BUG_ON(pipe_index >= px_num(chip))) return -EINVAL;

• if (snd_BUG_ON(!is_pipe_allocated(chip, pipe_index)))

• /*

• * We passed checks we can do independently; now take
  

• * exclusive control
  

• */
  

• spin_lock(&chip->lock);

You need spin_lock_irq() and spin_unlock_irq(), as the prepare callback in in sleepable context.

thanks,

Takashi