Commit 8009d506 authored by Ben Hutchings's avatar Ben Hutchings Committed by Takashi Iwai
Browse files

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: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 9bb201a5

sound/core/seq/seq_lock.c

+0 −4
Original line number Diff line number Diff line
@@ -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

sound/core/seq/seq_lock.h

+0 −12
Original line number Diff line number Diff line
@@ -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 */

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