ALSA: core: don't return uninitialized snd_compr_tstamp
The snd_compr_update_tstamp() can only fill in the snd_compr_tstamp
if the codec implements the pointer() function. If that happened
the code was previously returning uninitialized garbage in the
tstamp because it wasn't initialized anywhere.
This change zero-fills the tstamp in the two places it is used
before calling snd_compr_update_tstamp(), and also has
snd_compr_update_tstamp() return an error indication if it
can't provide a tstamp. For the case of snd_compr_calc_avail()
it ignores this error because we still need to return info on
the available buffer space even if we can't provide tstamp
info - when the tstamp is not valid all fields are now
guaranteed to be zero.
Change-Id: Ib3287720a05861f358561dbcc465a2ea685945db
Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Krishnankutty Kolathappilly <kkolat@codeaurora.org>
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index c40ae57..d9e08fc 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -139,16 +139,17 @@
return 0;
}
-static void snd_compr_update_tstamp(struct snd_compr_stream *stream,
+static int snd_compr_update_tstamp(struct snd_compr_stream *stream,
struct snd_compr_tstamp *tstamp)
{
if (!stream->ops->pointer)
- return;
+ return -ENOTSUPP;
stream->ops->pointer(stream, tstamp);
pr_debug("dsp consumed till %d total %d bytes\n",
tstamp->byte_offset, tstamp->copied_total);
stream->runtime->hw_pointer = tstamp->byte_offset;
stream->runtime->total_bytes_transferred = tstamp->copied_total;
+ return 0;
}
static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
@@ -156,7 +157,9 @@
{
long avail_calc; /*this needs to be signed variable */
+ memset(avail, 0, sizeof(*avail));
snd_compr_update_tstamp(stream, &avail->tstamp);
+ /* Still need to return avail even if tstamp can't be filled in */
/* FIXME: This needs to be different for capture stream,
available is # of compressed data, for playback it's
@@ -512,11 +515,14 @@
static inline int
snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
{
- struct snd_compr_tstamp tstamp;
+ struct snd_compr_tstamp tstamp = {0};
+ int ret;
- snd_compr_update_tstamp(stream, &tstamp);
- return copy_to_user((struct snd_compr_tstamp __user *)arg,
- &tstamp, sizeof(tstamp)) ? -EFAULT : 0;
+ ret = snd_compr_update_tstamp(stream, &tstamp);
+ if (ret == 0)
+ ret = copy_to_user((struct snd_compr_tstamp __user *)arg,
+ &tstamp, sizeof(tstamp)) ? -EFAULT : 0;
+ return ret;
}
static int snd_compr_pause(struct snd_compr_stream *stream)