[ALSA] timer - added tread semaphore
Timer Midlevel
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/core/timer.c b/sound/core/timer.c
index fa762ca..be6d37a 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -69,6 +69,7 @@
struct timespec tstamp; /* trigger tstamp */
wait_queue_head_t qchange_sleep;
struct fasync_struct *fasync;
+ struct semaphore tread_sem;
} snd_timer_user_t;
/* list of timers */
@@ -1208,6 +1209,7 @@
return -ENOMEM;
spin_lock_init(&tu->qlock);
init_waitqueue_head(&tu->qchange_sleep);
+ init_MUTEX(&tu->tread_sem);
tu->ticks = 1;
tu->queue_size = 128;
tu->queue = (snd_timer_read_t *)kmalloc(tu->queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
@@ -1454,18 +1456,23 @@
snd_timer_user_t *tu;
snd_timer_select_t tselect;
char str[32];
- int err;
+ int err = 0;
tu = file->private_data;
- if (tu->timeri)
+ down(&tu->tread_sem);
+ if (tu->timeri) {
snd_timer_close(tu->timeri);
- if (copy_from_user(&tselect, _tselect, sizeof(tselect)))
- return -EFAULT;
+ tu->timeri = NULL;
+ }
+ if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
+ err = -EFAULT;
+ goto __err;
+ }
sprintf(str, "application %i", current->pid);
if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
if ((err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid)) < 0)
- return err;
+ goto __err;
if (tu->queue) {
kfree(tu->queue);
@@ -1477,23 +1484,27 @@
}
if (tu->tread) {
tu->tqueue = (snd_timer_tread_t *)kmalloc(tu->queue_size * sizeof(snd_timer_tread_t), GFP_KERNEL);
- if (tu->tqueue == NULL) {
- snd_timer_close(tu->timeri);
- return -ENOMEM;
- }
+ if (tu->tqueue == NULL)
+ err = -ENOMEM;
} else {
tu->queue = (snd_timer_read_t *)kmalloc(tu->queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
- if (tu->queue == NULL) {
- snd_timer_close(tu->timeri);
- return -ENOMEM;
- }
+ if (tu->queue == NULL)
+ err = -ENOMEM;
}
- tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
- tu->timeri->callback = tu->tread ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
- tu->timeri->ccallback = snd_timer_user_ccallback;
- tu->timeri->callback_data = (void *)tu;
- return 0;
+ if (err < 0) {
+ snd_timer_close(tu->timeri);
+ tu->timeri = NULL;
+ } else {
+ tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
+ tu->timeri->callback = tu->tread ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
+ tu->timeri->ccallback = snd_timer_user_ccallback;
+ tu->timeri->callback_data = (void *)tu;
+ }
+
+ __err:
+ up(&tu->tread_sem);
+ return err;
}
static int snd_timer_user_info(struct file *file, snd_timer_info_t __user *_info)
@@ -1685,11 +1696,17 @@
{
int xarg;
- if (tu->timeri) /* too late */
+ down(&tu->tread_sem);
+ if (tu->timeri) { /* too late */
+ up(&tu->tread_sem);
return -EBUSY;
- if (get_user(xarg, p))
+ }
+ if (get_user(xarg, p)) {
+ up(&tu->tread_sem);
return -EFAULT;
+ }
tu->tread = xarg ? 1 : 0;
+ up(&tu->tread_sem);
return 0;
}
case SNDRV_TIMER_IOCTL_GINFO: