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>

1 files changed, 18 insertions, 25 deletions

diff --git a/sound/usb/usx2y/us122l.c b/sound/usb/usx2y/us122l.c
index 159da1f3924e..8c394178a385 100644
--- a/sound/usb/usx2y/us122l.c
+++ b/sound/usb/usx2y/us122l.c
@@ -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;
 }