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ALSA: seq: Enable 'use' locking in all configurations 

The 'use' locking macros are no-ops if neither SMP or SND_DEBUG is
enabled.  This might once have been OK in non-preemptible
configurations, but even in that case snd_seq_read() may sleep while
relying on a 'use' lock.  So always use the proper implementations.

Cc: stable@vger.kernel.org
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Ben Hutchings 2017-10-18 00:45:49 +01:00 committed by Takashi Iwai
parent 9bb201a5d5
commit 8009d506a1
2 changed files with 0 additions and 16 deletions
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4
sound/core/seq/seq_lock.c
View File

@ -23,8 +23,6 @@
#include <sound/core.h>
#include "seq_lock.h"
#if defined(CONFIG_SMP) || defined(CONFIG_SND_DEBUG)
/* wait until all locks are released */
void snd_use_lock_sync_helper(snd_use_lock_t *lockp, const char *file, int line)
{
@ -41,5 +39,3 @@ void snd_use_lock_sync_helper(snd_use_lock_t *lockp, const char *file, int line)
}
}
EXPORT_SYMBOL(snd_use_lock_sync_helper);
#endif

12
sound/core/seq/seq_lock.h
View File

@ -3,8 +3,6 @@
#include <linux/sched.h>
#if defined(CONFIG_SMP) || defined(CONFIG_SND_DEBUG)
typedef atomic_t snd_use_lock_t;
/* initialize lock */
@ -20,14 +18,4 @@ typedef atomic_t snd_use_lock_t;
void snd_use_lock_sync_helper(snd_use_lock_t *lock, const char *file, int line);
#define snd_use_lock_sync(lockp) snd_use_lock_sync_helper(lockp, __BASE_FILE__, __LINE__)
#else /* SMP || CONFIG_SND_DEBUG */
typedef spinlock_t snd_use_lock_t; /* dummy */
#define snd_use_lock_init(lockp) /**/
#define snd_use_lock_use(lockp) /**/
#define snd_use_lock_free(lockp) /**/
#define snd_use_lock_sync(lockp) /**/
#endif /* SMP || CONFIG_SND_DEBUG */
#endif /* __SND_SEQ_LOCK_H */