[PATCH] locking: annotate inline spinlocks and rwlocks on SMP
From: Pavel Roskin
Date: Tue Mar 09 2010 - 20:01:08 EST
When spinlock or rwlock functions are inlined on SMP, their definitions
are not annotated for sparse.
In particular, SMP kernels without CONFIG_PREEMPT and lock debugging
would inline spin_unlock(), but not spin_lock(), resulting in bogus
sparse warnings about locking.
Use __acquire() and __release() to annotate inline spinlocks in the same
way as their non-inline implementations are annotated.
Signed-off-by: Pavel Roskin <proski@xxxxxxx>
---
The new code has been tested by forcing all spinlocks and rwlocks to be
inlined. The _raw_*_irqsave() functions return long (the flags) on SMP,
so compound statements are used for them. I ran sparse on the whole
kernel, and whenever sparse complains about locking, the code is
non-trivial. I'm running the patched kernel now.
include/linux/rwlock_api_smp.h | 98 +++++++++++++++++++++++++++++++-------
include/linux/spinlock_api_smp.h | 48 ++++++++++++++++---
2 files changed, 120 insertions(+), 26 deletions(-)
diff --git a/include/linux/rwlock_api_smp.h b/include/linux/rwlock_api_smp.h
index 9c9f049..c16c3ee 100644
--- a/include/linux/rwlock_api_smp.h
+++ b/include/linux/rwlock_api_smp.h
@@ -41,35 +41,67 @@ _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
__releases(lock);
#ifdef CONFIG_INLINE_READ_LOCK
-#define _raw_read_lock(lock) __raw_read_lock(lock)
+#define _raw_read_lock(lock) \
+ do { \
+ __acquire(lock); \
+ __raw_read_lock(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_WRITE_LOCK
-#define _raw_write_lock(lock) __raw_write_lock(lock)
+#define _raw_write_lock(lock) \
+ do { \
+ __acquire(lock); \
+ __raw_write_lock(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_READ_LOCK_BH
-#define _raw_read_lock_bh(lock) __raw_read_lock_bh(lock)
+#define _raw_read_lock_bh(lock) \
+ do { \
+ __acquire(lock); \
+ __raw_read_lock_bh(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_WRITE_LOCK_BH
-#define _raw_write_lock_bh(lock) __raw_write_lock_bh(lock)
+#define _raw_write_lock_bh(lock) \
+ do { \
+ __acquire(lock); \
+ __raw_write_lock_bh(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_READ_LOCK_IRQ
-#define _raw_read_lock_irq(lock) __raw_read_lock_irq(lock)
+#define _raw_read_lock_irq(lock) \
+ do { \
+ __acquire(lock); \
+ __raw_read_lock_irq(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_WRITE_LOCK_IRQ
-#define _raw_write_lock_irq(lock) __raw_write_lock_irq(lock)
+#define _raw_write_lock_irq(lock) \
+ do { \
+ __acquire(lock); \
+ __raw_write_lock_irq(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_READ_LOCK_IRQSAVE
-#define _raw_read_lock_irqsave(lock) __raw_read_lock_irqsave(lock)
+#define _raw_read_lock_irqsave(lock) \
+ ({ \
+ __acquire(lock); \
+ __raw_read_lock_irqsave(lock); \
+ })
#endif
#ifdef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
-#define _raw_write_lock_irqsave(lock) __raw_write_lock_irqsave(lock)
+#define _raw_write_lock_irqsave(lock) \
+ ({ \
+ __acquire(lock); \
+ __raw_write_lock_irqsave(lock); \
+ })
#endif
#ifdef CONFIG_INLINE_READ_TRYLOCK
@@ -81,37 +113,67 @@ _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
#endif
#ifdef CONFIG_INLINE_READ_UNLOCK
-#define _raw_read_unlock(lock) __raw_read_unlock(lock)
+#define _raw_read_unlock(lock) \
+ do { \
+ __raw_read_unlock(lock); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_WRITE_UNLOCK
-#define _raw_write_unlock(lock) __raw_write_unlock(lock)
+#define _raw_write_unlock(lock) \
+ do { \
+ __raw_write_unlock(lock); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_READ_UNLOCK_BH
-#define _raw_read_unlock_bh(lock) __raw_read_unlock_bh(lock)
+#define _raw_read_unlock_bh(lock) \
+ do { \
+ __raw_read_unlock_bh(lock); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_WRITE_UNLOCK_BH
-#define _raw_write_unlock_bh(lock) __raw_write_unlock_bh(lock)
+#define _raw_write_unlock_bh(lock) \
+ do { \
+ __raw_write_unlock_bh(lock); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_READ_UNLOCK_IRQ
-#define _raw_read_unlock_irq(lock) __raw_read_unlock_irq(lock)
+#define _raw_read_unlock_irq(lock) \
+ do { \
+ __raw_read_unlock_irq(lock); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_WRITE_UNLOCK_IRQ
-#define _raw_write_unlock_irq(lock) __raw_write_unlock_irq(lock)
+#define _raw_write_unlock_irq(lock) \
+ do { \
+ __raw_write_unlock_irq(lock); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE
-#define _raw_read_unlock_irqrestore(lock, flags) \
- __raw_read_unlock_irqrestore(lock, flags)
+#define _raw_read_unlock_irqrestore(lock, flags) \
+ do { \
+ __raw_read_unlock_irqrestore(lock, flags); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE
-#define _raw_write_unlock_irqrestore(lock, flags) \
- __raw_write_unlock_irqrestore(lock, flags)
+#define _raw_write_unlock_irqrestore(lock, flags) \
+ do { \
+ __raw_write_unlock_irqrestore(lock, flags); \
+ __release(lock); \
+ } while (0)
#endif
static inline int __raw_read_trylock(rwlock_t *lock)
diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h
index e253ccd..6fb9ecb 100644
--- a/include/linux/spinlock_api_smp.h
+++ b/include/linux/spinlock_api_smp.h
@@ -44,19 +44,35 @@ _raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)
__releases(lock);
#ifdef CONFIG_INLINE_SPIN_LOCK
-#define _raw_spin_lock(lock) __raw_spin_lock(lock)
+#define _raw_spin_lock(lock) \
+ do { \
+ __acquire(lock); \
+ __raw_spin_lock(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_SPIN_LOCK_BH
-#define _raw_spin_lock_bh(lock) __raw_spin_lock_bh(lock)
+#define _raw_spin_lock_bh(lock) \
+ do { \
+ __acquire(lock); \
+ __raw_spin_lock_bh(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_SPIN_LOCK_IRQ
-#define _raw_spin_lock_irq(lock) __raw_spin_lock_irq(lock)
+#define _raw_spin_lock_irq(lock) \
+ do { \
+ __acquire(lock); \
+ __raw_spin_lock_irq(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
-#define _raw_spin_lock_irqsave(lock) __raw_spin_lock_irqsave(lock)
+#define _raw_spin_lock_irqsave(lock) \
+ ({ \
+ __acquire(lock); \
+ __raw_spin_lock_irqsave(lock); \
+ })
#endif
#ifdef CONFIG_INLINE_SPIN_TRYLOCK
@@ -68,19 +84,35 @@ _raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)
#endif
#ifdef CONFIG_INLINE_SPIN_UNLOCK
-#define _raw_spin_unlock(lock) __raw_spin_unlock(lock)
+#define _raw_spin_unlock(lock) \
+ do { \
+ __raw_spin_unlock(lock); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_SPIN_UNLOCK_BH
-#define _raw_spin_unlock_bh(lock) __raw_spin_unlock_bh(lock)
+#define _raw_spin_unlock_bh(lock) \
+ do { \
+ __raw_spin_unlock_bh(lock); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_SPIN_UNLOCK_IRQ
-#define _raw_spin_unlock_irq(lock) __raw_spin_unlock_irq(lock)
+#define _raw_spin_unlock_irq(lock) \
+ do { \
+ __raw_spin_unlock_irq(lock); \
+ __release(lock); \
+ } while (0)
#endif
#ifdef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
-#define _raw_spin_unlock_irqrestore(lock, flags) __raw_spin_unlock_irqrestore(lock, flags)
+#define _raw_spin_unlock_irqrestore(lock, flags) \
+ do { \
+ __raw_spin_unlock_irqrestore(lock, flags); \
+ __release(lock); \
+ } while (0)
#endif
static inline int __raw_spin_trylock(raw_spinlock_t *lock)
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