pcm: meter / s16 - add protection for the maximum copied frames

The rewind or forward may cause the stream pointer change. Although
this patch does not fix the real meter update issue, it breaks
the possible big loops when the stream pointers are desynced with
the meters. It does not make sense to copy more samples than the
pcm buffer contains.

Link: https://lore.kernel.org/alsa-devel/f56d6a67-014a-e562-c253-830c0ec03717@ivitera.com/
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Jaroslav Kysela 2020-10-13 19:28:29 +02:00
parent aa89ad9362
commit a6c8ac0c85

View file

@ -79,6 +79,8 @@ static void snd_pcm_meter_add_frames(snd_pcm_t *pcm,
snd_pcm_uframes_t frames) snd_pcm_uframes_t frames)
{ {
snd_pcm_meter_t *meter = pcm->private_data; snd_pcm_meter_t *meter = pcm->private_data;
if (frames > pcm->buffer_size)
frames = pcm->buffer_size;
while (frames > 0) { while (frames > 0) {
snd_pcm_uframes_t n = frames; snd_pcm_uframes_t n = frames;
snd_pcm_uframes_t dst_offset = ptr % meter->buf_size; snd_pcm_uframes_t dst_offset = ptr % meter->buf_size;
@ -1100,6 +1102,8 @@ static void s16_update(snd_pcm_scope_t *scope)
size = meter->now - s16->old; size = meter->now - s16->old;
if (size < 0) if (size < 0)
size += spcm->boundary; size += spcm->boundary;
if (size > (snd_pcm_sframes_t)s16->pcm->buffer_size)
size = s16->pcm->buffer_size;
offset = s16->old % meter->buf_size; offset = s16->old % meter->buf_size;
while (size > 0) { while (size > 0) {
snd_pcm_uframes_t frames = size; snd_pcm_uframes_t frames = size;