diff options
| author | Takashi Iwai <tiwai@suse.de> | 2017-06-02 17:35:30 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2017-06-07 10:25:53 +0200 |
| commit | d7f910bfedd863d13ea320030fe98e42d0938ed5 (patch) | |
| tree | 51ec98386371c6adead80f99ee88a42ccb6dbb19 | |
| parent | ALSA: timer: Improve user queue reallocation (diff) | |
| download | linux-d7f910bfedd863d13ea320030fe98e42d0938ed5.tar.xz linux-d7f910bfedd863d13ea320030fe98e42d0938ed5.zip | |
ALSA: timer: Wrap with spinlock for queue access
For accessing the snd_timer_user queue indices, we take tu->qlock.
But it's forgotten in a couple of places.
The one in snd_timer_user_params() should be safe without the
spinlock as the timer is already stopped. But it's better for
consistency.
The one in poll is just a read-out, so it's not inevitably needed, but
it'd be good to make the result consistent, too.
Tested-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | sound/core/timer.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/sound/core/timer.c b/sound/core/timer.c index 96cffb1be57f..148290ace756 100644 --- a/sound/core/timer.c +++ b/sound/core/timer.c @@ -1755,6 +1755,7 @@ static int snd_timer_user_params(struct file *file, if (err < 0) goto _end; } + spin_lock_irq(&tu->qlock); tu->qhead = tu->qtail = tu->qused = 0; if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) { if (tu->tread) { @@ -1775,6 +1776,7 @@ static int snd_timer_user_params(struct file *file, } tu->filter = params.filter; tu->ticks = params.ticks; + spin_unlock_irq(&tu->qlock); err = 0; _end: if (copy_to_user(_params, ¶ms, sizeof(params))) @@ -2022,10 +2024,12 @@ static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait) poll_wait(file, &tu->qchange_sleep, wait); mask = 0; + spin_lock_irq(&tu->qlock); if (tu->qused) mask |= POLLIN | POLLRDNORM; if (tu->disconnected) mask |= POLLERR; + spin_unlock_irq(&tu->qlock); return mask; } |