Messages in this thread Patch in this message | | | Subject | [PATCH] locking: annotate inline spinlocks and rwlocks on SMP | From | Pavel Roskin <> | Date | Tue, 09 Mar 2010 20:00:59 -0500 |
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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@gnu.org> ---
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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