linux/sound/firewire/fireworks
Takashi Sakamoto 6b1ca4bcad ALSA: fireworks: accessing to user space outside spinlock
In hwdep interface of fireworks driver, accessing to user space is in a
critical section with disabled local interrupt. Depending on architecture,
accessing to user space can cause page fault exception. Then local
processor stores machine status and handles the synchronous event. A
handler corresponding to the event can call task scheduler to wait for
preparing pages. In a case of usage of single core processor, the state to
disable local interrupt is worse because it don't handle usual interrupts
from hardware.

This commit fixes this bug, performing the accessing outside spinlock. This
commit also gives up counting the number of queued response messages to
simplify ring-buffer management.

Reported-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Cc: stable@vger.kernel.org
Fixes: 555e8a8f7f14('ALSA: fireworks: Add command/response functionality into hwdep interface')
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-31 16:17:15 +02:00
..
Makefile ALSA: fireworks/bebob/oxfw/dice: enable to make as built-in 2015-10-18 09:08:11 +02:00
fireworks.c ALSA: fireworks: delayed registration of sound card 2016-03-31 15:36:19 +02:00
fireworks.h ALSA: fireworks: accessing to user space outside spinlock 2016-08-31 16:17:15 +02:00
fireworks_command.c ALSA: fireworks: use u32 type for be32_to_cpup() macro 2015-10-19 11:57:02 +02:00
fireworks_hwdep.c ALSA: fireworks: accessing to user space outside spinlock 2016-08-31 16:17:15 +02:00
fireworks_midi.c ALSA: fireworks: change type of substream counter from atomic_t to unsigned int 2015-11-14 17:53:46 +01:00
fireworks_pcm.c ALSA: fireworks: change type of substream counter from atomic_t to unsigned int 2015-11-14 17:53:46 +01:00
fireworks_proc.c ALSA: fireworks: accessing to user space outside spinlock 2016-08-31 16:17:15 +02:00
fireworks_stream.c ALSA: fireworks: drop reuse of incoming packet parameter for ougoing packet parameter 2016-05-10 17:03:58 +02:00
fireworks_transaction.c ALSA: fireworks: accessing to user space outside spinlock 2016-08-31 16:17:15 +02:00