| From 0375367f248abc145c47754409b4e1fde0842594 Mon Sep 17 00:00:00 2001 |
| From: Takashi Sakamoto <o-takashi@sakamocchi.jp> |
| Date: Mon, 13 Jan 2020 17:57:19 +0900 |
| Subject: [PATCH] ALSA: firewire-tascam: fix corruption due to spin lock |
| without restoration in SoftIRQ context |
| |
| commit 747d1f076de5a60770011f6e512de43298ec64cb upstream. |
| |
| ALSA firewire-tascam driver can bring corruption due to spin lock without |
| restoration of IRQ flag in SoftIRQ context. This commit fixes the bug. |
| |
| Cc: Scott Bahling <sbahling@suse.com> |
| Cc: <stable@vger.kernel.org> # v4.21 |
| Fixes: d7167422433c ("ALSA: firewire-tascam: queue events for change of control surface") |
| Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> |
| Link: https://lore.kernel.org/r/20200113085719.26788-1-o-takashi@sakamocchi.jp |
| Signed-off-by: Takashi Iwai <tiwai@suse.de> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/sound/firewire/tascam/amdtp-tascam.c b/sound/firewire/tascam/amdtp-tascam.c |
| index d9d20ef22f5b..9d7263aed2b4 100644 |
| --- a/sound/firewire/tascam/amdtp-tascam.c |
| +++ b/sound/firewire/tascam/amdtp-tascam.c |
| @@ -147,14 +147,15 @@ static void read_status_messages(struct amdtp_stream *s, |
| if ((before ^ after) & mask) { |
| struct snd_firewire_tascam_change *entry = |
| &tscm->queue[tscm->push_pos]; |
| + unsigned long flag; |
| |
| - spin_lock_irq(&tscm->lock); |
| + spin_lock_irqsave(&tscm->lock, flag); |
| entry->index = index; |
| entry->before = before; |
| entry->after = after; |
| if (++tscm->push_pos >= SND_TSCM_QUEUE_COUNT) |
| tscm->push_pos = 0; |
| - spin_unlock_irq(&tscm->lock); |
| + spin_unlock_irqrestore(&tscm->lock, flag); |
| |
| wake_up(&tscm->hwdep_wait); |
| } |
| -- |
| 2.7.4 |
| |
