pcm: another weird API abuse
readv() and writev() should _not_ ignore all but the first ->iov_len,
among other things. Really weird abuse of those syscalls - it
expects a vector element per channel, with identical lengths (it
actually assumes them to be identical - no checking is done).
readv() and writev() are really bad match for that. Unfortunately,
userland API is userland API and we can't do anything about them.
Converted to ->read_iter/->write_iter. Please, _please_ don't do
anything of that kind when designing new interfaces.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index a69ebc7..8e43610 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3033,9 +3033,7 @@
return result;
}
-static ssize_t snd_pcm_aio_read(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
-
+static ssize_t snd_pcm_readv(struct kiocb *iocb, struct iov_iter *to)
{
struct snd_pcm_file *pcm_file;
struct snd_pcm_substream *substream;
@@ -3052,16 +3050,18 @@
runtime = substream->runtime;
if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
return -EBADFD;
- if (nr_segs > 1024 || nr_segs != runtime->channels)
+ if (!iter_is_iovec(to))
return -EINVAL;
- if (!frame_aligned(runtime, iov->iov_len))
+ if (to->nr_segs > 1024 || to->nr_segs != runtime->channels)
return -EINVAL;
- frames = bytes_to_samples(runtime, iov->iov_len);
- bufs = kmalloc(sizeof(void *) * nr_segs, GFP_KERNEL);
+ if (!frame_aligned(runtime, to->iov->iov_len))
+ return -EINVAL;
+ frames = bytes_to_samples(runtime, to->iov->iov_len);
+ bufs = kmalloc(sizeof(void *) * to->nr_segs, GFP_KERNEL);
if (bufs == NULL)
return -ENOMEM;
- for (i = 0; i < nr_segs; ++i)
- bufs[i] = iov[i].iov_base;
+ for (i = 0; i < to->nr_segs; ++i)
+ bufs[i] = to->iov[i].iov_base;
result = snd_pcm_lib_readv(substream, bufs, frames);
if (result > 0)
result = frames_to_bytes(runtime, result);
@@ -3069,8 +3069,7 @@
return result;
}
-static ssize_t snd_pcm_aio_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
+static ssize_t snd_pcm_writev(struct kiocb *iocb, struct iov_iter *from)
{
struct snd_pcm_file *pcm_file;
struct snd_pcm_substream *substream;
@@ -3087,15 +3086,17 @@
runtime = substream->runtime;
if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
return -EBADFD;
- if (nr_segs > 128 || nr_segs != runtime->channels ||
- !frame_aligned(runtime, iov->iov_len))
+ if (!iter_is_iovec(from))
return -EINVAL;
- frames = bytes_to_samples(runtime, iov->iov_len);
- bufs = kmalloc(sizeof(void *) * nr_segs, GFP_KERNEL);
+ if (from->nr_segs > 128 || from->nr_segs != runtime->channels ||
+ !frame_aligned(runtime, from->iov->iov_len))
+ return -EINVAL;
+ frames = bytes_to_samples(runtime, from->iov->iov_len);
+ bufs = kmalloc(sizeof(void *) * from->nr_segs, GFP_KERNEL);
if (bufs == NULL)
return -ENOMEM;
- for (i = 0; i < nr_segs; ++i)
- bufs[i] = iov[i].iov_base;
+ for (i = 0; i < from->nr_segs; ++i)
+ bufs[i] = from->iov[i].iov_base;
result = snd_pcm_lib_writev(substream, bufs, frames);
if (result > 0)
result = frames_to_bytes(runtime, result);
@@ -3633,7 +3634,7 @@
{
.owner = THIS_MODULE,
.write = snd_pcm_write,
- .aio_write = snd_pcm_aio_write,
+ .write_iter = snd_pcm_writev,
.open = snd_pcm_playback_open,
.release = snd_pcm_release,
.llseek = no_llseek,
@@ -3647,7 +3648,7 @@
{
.owner = THIS_MODULE,
.read = snd_pcm_read,
- .aio_read = snd_pcm_aio_read,
+ .read_iter = snd_pcm_readv,
.open = snd_pcm_capture_open,
.release = snd_pcm_release,
.llseek = no_llseek,