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| author | Takashi Iwai <tiwai@suse.de> | 2022-03-22 18:13:25 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2022-03-22 20:57:15 +0100 |
| commit | 1f68915b2efd0d6bfd6e124aa63c94b3c69f127c (patch) | |
| tree | 8ecc866b1820296c074e8a6d1bc8231d944b8c8d /sound | |
| parent | 69534c48ba8ce552ce383b3dfdb271ffe51820c3 (diff) | |
| download | lwn-1f68915b2efd0d6bfd6e124aa63c94b3c69f127c.tar.gz lwn-1f68915b2efd0d6bfd6e124aa63c94b3c69f127c.zip | |
ALSA: pcm: Add stream lock during PCM reset ioctl operations
snd_pcm_reset() is a non-atomic operation, and it's allowed to run
during the PCM stream running. It implies that the manipulation of
hw_ptr and other parameters might be racy.
This patch adds the PCM stream lock at appropriate places in
snd_pcm_*_reset() actions for covering that.
Cc: <stable@vger.kernel.org>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220322171325.4355-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/core/pcm_native.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 0e4fbf5fd87b..704fdc9ebf91 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -1864,11 +1864,13 @@ static int snd_pcm_do_reset(struct snd_pcm_substream *substream, int err = snd_pcm_ops_ioctl(substream, SNDRV_PCM_IOCTL1_RESET, NULL); if (err < 0) return err; + snd_pcm_stream_lock_irq(substream); runtime->hw_ptr_base = 0; runtime->hw_ptr_interrupt = runtime->status->hw_ptr - runtime->status->hw_ptr % runtime->period_size; runtime->silence_start = runtime->status->hw_ptr; runtime->silence_filled = 0; + snd_pcm_stream_unlock_irq(substream); return 0; } @@ -1876,10 +1878,12 @@ static void snd_pcm_post_reset(struct snd_pcm_substream *substream, snd_pcm_state_t state) { struct snd_pcm_runtime *runtime = substream->runtime; + snd_pcm_stream_lock_irq(substream); runtime->control->appl_ptr = runtime->status->hw_ptr; if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && runtime->silence_size > 0) snd_pcm_playback_silence(substream, ULONG_MAX); + snd_pcm_stream_unlock_irq(substream); } static const struct action_ops snd_pcm_action_reset = { |