diff options
| author | Arjan van de Ven <arjan@infradead.org> | 2006-07-04 03:07:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-07-04 10:24:57 -0700 |
| commit | c6482dde1c2811afba289b2344268f850595f350 (patch) | |
| tree | bfd2ab0c2bcfe6fe4de64bab40f2c19f25131a97 /sound/pci/cs46xx | |
| parent | a46f9484f8926aacb2e79a0e1676de3a6a6fbae8 (diff) | |
| download | linux-c6482dde1c2811afba289b2344268f850595f350.tar.gz | |
[PATCH] fix AB-BA deadlock inversion at cs46xx_dsp_remove_scb
There is a code sequence where the locking is substream->self_group.lock -> ins->scbs[index].lock substream->self_group.lock is interrupt safe, and taken from irq context as well (trace is snipped for brevity) so what can happen is cpu 0 cpu 1 user context user context take ins->scbs[index].lock without disabling interrupts get substream->self_group.lock (irqsafe) try to get ins->scbs[index].lock (spins) interrupt happens try to get substream->self_group.lock (spins) which is an obvious AB-BA deadlock fix is to just take the lock with _irqsafe Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Jaroslav Kysela <perex@suse.cz> Acked-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'sound/pci/cs46xx')
| -rw-r--r-- | sound/pci/cs46xx/dsp_spos_scb_lib.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/sound/pci/cs46xx/dsp_spos_scb_lib.c b/sound/pci/cs46xx/dsp_spos_scb_lib.c index 3844d18af19c..232b337852ff 100644 --- a/sound/pci/cs46xx/dsp_spos_scb_lib.c +++ b/sound/pci/cs46xx/dsp_spos_scb_lib.c @@ -180,6 +180,7 @@ static void _dsp_clear_sample_buffer (struct snd_cs46xx *chip, u32 sample_buffer void cs46xx_dsp_remove_scb (struct snd_cs46xx *chip, struct dsp_scb_descriptor * scb) { struct dsp_spos_instance * ins = chip->dsp_spos_instance; + unsigned long flags; /* check integrety */ snd_assert ( (scb->index >= 0 && @@ -194,9 +195,9 @@ void cs46xx_dsp_remove_scb (struct snd_cs46xx *chip, struct dsp_scb_descriptor * goto _end); #endif - spin_lock(&scb->lock); + spin_lock_irqsave(&scb->lock, flags); _dsp_unlink_scb (chip,scb); - spin_unlock(&scb->lock); + spin_unlock_irqrestore(&scb->lock, flags); cs46xx_dsp_proc_free_scb_desc(scb); snd_assert (scb->scb_symbol != NULL, return ); |