[PATCH 4.13 45/85] ALSA: seq: Enable use locking in all configurations
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2017-10-24 13:19:03
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4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings <redacted> commit 8009d506a1dd00cf436b0c4cca0dcec130580a21 upstream. 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. Signed-off-by: Ben Hutchings <redacted> Signed-off-by: Takashi Iwai <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- sound/core/seq/seq_lock.c | 4 ---- sound/core/seq/seq_lock.h | 12 ------------ 2 files changed, 16 deletions(-)
--- a/sound/core/seq/seq_lock.c
+++ b/sound/core/seq/seq_lock.c@@ -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_lo } } EXPORT_SYMBOL(snd_use_lock_sync_helper); - -#endif --- a/sound/core/seq/seq_lock.h +++ b/sound/core/seq/seq_lock.h
@@ -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 */