usx2y: don't bother with memdup_user() for 16-byte structure

... when it can bloody well go into a local variable.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2017-12-28 17:22:51 -05:00
parent 446bd647ce
commit 3d46d7108d

View file

@ -378,7 +378,7 @@ out:
static int usb_stream_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
unsigned cmd, unsigned long arg)
{
struct usb_stream_config *cfg;
struct usb_stream_config cfg;
struct us122l *us122l = hw->private_data;
struct usb_stream *s;
unsigned min_period_frames;
@ -388,24 +388,21 @@ static int usb_stream_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
if (cmd != SNDRV_USB_STREAM_IOCTL_SET_PARAMS)
return -ENOTTY;
cfg = memdup_user((void *)arg, sizeof(*cfg));
if (IS_ERR(cfg))
return PTR_ERR(cfg);
if (copy_from_user(&cfg, (void __user *)arg, sizeof(cfg)))
return -EFAULT;
if (cfg.version != USB_STREAM_INTERFACE_VERSION)
return -ENXIO;
if (cfg->version != USB_STREAM_INTERFACE_VERSION) {
err = -ENXIO;
goto free;
}
high_speed = us122l->dev->speed == USB_SPEED_HIGH;
if ((cfg->sample_rate != 44100 && cfg->sample_rate != 48000 &&
if ((cfg.sample_rate != 44100 && cfg.sample_rate != 48000 &&
(!high_speed ||
(cfg->sample_rate != 88200 && cfg->sample_rate != 96000))) ||
cfg->frame_size != 6 ||
cfg->period_frames > 0x3000) {
err = -EINVAL;
goto free;
}
switch (cfg->sample_rate) {
(cfg.sample_rate != 88200 && cfg.sample_rate != 96000))) ||
cfg.frame_size != 6 ||
cfg.period_frames > 0x3000)
return -EINVAL;
switch (cfg.sample_rate) {
case 44100:
min_period_frames = 48;
break;
@ -418,10 +415,8 @@ static int usb_stream_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
}
if (!high_speed)
min_period_frames <<= 1;
if (cfg->period_frames < min_period_frames) {
err = -EINVAL;
goto free;
}
if (cfg.period_frames < min_period_frames)
return -EINVAL;
snd_power_wait(hw->card, SNDRV_CTL_POWER_D0);
@ -430,24 +425,22 @@ static int usb_stream_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
if (!us122l->master)
us122l->master = file;
else if (us122l->master != file) {
if (!s || memcmp(cfg, &s->cfg, sizeof(*cfg))) {
if (!s || memcmp(&cfg, &s->cfg, sizeof(cfg))) {
err = -EIO;
goto unlock;
}
us122l->slave = file;
}
if (!s || memcmp(cfg, &s->cfg, sizeof(*cfg)) ||
if (!s || memcmp(&cfg, &s->cfg, sizeof(cfg)) ||
s->state == usb_stream_xrun) {
us122l_stop(us122l);
if (!us122l_start(us122l, cfg->sample_rate, cfg->period_frames))
if (!us122l_start(us122l, cfg.sample_rate, cfg.period_frames))
err = -EIO;
else
err = 1;
}
unlock:
mutex_unlock(&us122l->mutex);
free:
kfree(cfg);
wake_up_all(&us122l->sk.sleep);
return err;
}