copy_from/to_iter() returns the actually copied bytes, and the more
correct check should be to compare with the given bytes, instead of
zero-check.
Fixes: cf393babb37a ("ALSA: pcm: Add copy ops with iov_iter")
Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Closes: https://lore.kernel.org/r/20230902053044.GJ3390869@ZenIV
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/core/pcm_lib.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 4859fb1caec9..a11cd7d6295f 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1992,8 +1992,8 @@ static int default_write_copy(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
struct iov_iter *iter, unsigned long bytes)
{
- if (!copy_from_iter(get_dma_ptr(substream->runtime, channel, hwoff),
- bytes, iter))
+ if (copy_from_iter(get_dma_ptr(substream->runtime, channel, hwoff),
+ bytes, iter) != bytes)
return -EFAULT;
return 0;
}
@@ -2025,8 +2025,8 @@ static int default_read_copy(struct snd_pcm_substream *substream,
int channel, unsigned long hwoff,
struct iov_iter *iter, unsigned long bytes)
{
- if (!copy_to_iter(get_dma_ptr(substream->runtime, channel, hwoff),
- bytes, iter))
+ if (copy_to_iter(get_dma_ptr(substream->runtime, channel, hwoff),
+ bytes, iter) != bytes)
return -EFAULT;
return 0;
}
--
2.35.3
