ALSA: timer: fix gparams ioctl compatibility for different architectures

'struct snd_timer_gparams' includes some members with 'unsigned long',
therefore its size differs depending on data models of architecture. As
a result, x86/x32 applications fail to execute ioctl(2) with
SNDRV_TIMER_GPARAMS command on x86_64 machine.

This commit fixes this bug by adding a pair of structure and ioctl
command for the compatibility.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 13 insertions, 7 deletions

diff --git a/sound/core/timer.c b/sound/core/timer.c
index aa1b15c..ea4d999 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1502,17 +1502,13 @@ static int snd_timer_user_ginfo(struct file *file,
 	return err;
 }
 
-static int snd_timer_user_gparams(struct file *file,
-				  struct snd_timer_gparams __user *_gparams)
+static int timer_set_gparams(struct snd_timer_gparams *gparams)
 {
-	struct snd_timer_gparams gparams;
 	struct snd_timer *t;
 	int err;
 
-	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
-		return -EFAULT;
 	mutex_lock(&register_mutex);
-	t = snd_timer_find(&gparams.tid);
+	t = snd_timer_find(&gparams->tid);
 	if (!t) {
 		err = -ENODEV;
 		goto _error;
@@ -1525,12 +1521,22 @@ static int snd_timer_user_gparams(struct file *file,
 		err = -ENOSYS;
 		goto _error;
 	}
-	err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
+	err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
 _error:
 	mutex_unlock(&register_mutex);
 	return err;
 }
 
+static int snd_timer_user_gparams(struct file *file,
+				  struct snd_timer_gparams __user *_gparams)
+{
+	struct snd_timer_gparams gparams;
+
+	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
+		return -EFAULT;
+	return timer_set_gparams(&gparams);
+}
+
 static int snd_timer_user_gstatus(struct file *file,
 				  struct snd_timer_gstatus __user *_gstatus)
 {