1 files changed, 32 insertions, 22 deletions

diff --git a/include/linux/spinlock_up.h b/include/linux/spinlock_up.h
index 938234c4a99..8b3ac0d718e 100644
--- a/include/linux/spinlock_up.h
+++ b/include/linux/spinlock_up.h
@@ -5,6 +5,8 @@
 # error "please don't include this file directly"
 #endif
 
+#include <asm/processor.h>	/* for cpu_relax() */
+
 /*
  * include/linux/spinlock_up.h - UP-debug version of spinlocks.
  *
@@ -14,62 +16,70 @@
  * In the debug case, 1 means unlocked, 0 means locked. (the values
  * are inverted, to catch initialization bugs)
  *
- * No atomicity anywhere, we are on UP.
+ * No atomicity anywhere, we are on UP. However, we still need
+ * the compiler barriers, because we do not want the compiler to
+ * move potentially faulting instructions (notably user accesses)
+ * into the locked sequence, resulting in non-atomic execution.
  */
 
 #ifdef CONFIG_DEBUG_SPINLOCK
-#define __raw_spin_is_locked(x)		((x)->slock == 0)
+#define arch_spin_is_locked(x)		((x)->slock == 0)
 
-static inline void __raw_spin_lock(raw_spinlock_t *lock)
+static inline void arch_spin_lock(arch_spinlock_t *lock)
 {
 	lock->slock = 0;
+	barrier();
 }
 
 static inline void
-__raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
+arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
 {
 	local_irq_save(flags);
 	lock->slock = 0;
+	barrier();
 }
 
-static inline int __raw_spin_trylock(raw_spinlock_t *lock)
+static inline int arch_spin_trylock(arch_spinlock_t *lock)
 {
 	char oldval = lock->slock;
 
 	lock->slock = 0;
+	barrier();
 
 	return oldval > 0;
 }
 
-static inline void __raw_spin_unlock(raw_spinlock_t *lock)
+static inline void arch_spin_unlock(arch_spinlock_t *lock)
 {
+	barrier();
 	lock->slock = 1;
 }
 
 /*
  * Read-write spinlocks. No debug version.
  */
-#define __raw_read_lock(lock)		do { (void)(lock); } while (0)
-#define __raw_write_lock(lock)		do { (void)(lock); } while (0)
-#define __raw_read_trylock(lock)	({ (void)(lock); 1; })
-#define __raw_write_trylock(lock)	({ (void)(lock); 1; })
-#define __raw_read_unlock(lock)		do { (void)(lock); } while (0)
-#define __raw_write_unlock(lock)	do { (void)(lock); } while (0)
+#define arch_read_lock(lock)		do { barrier(); (void)(lock); } while (0)
+#define arch_write_lock(lock)		do { barrier(); (void)(lock); } while (0)
+#define arch_read_trylock(lock)	({ barrier(); (void)(lock); 1; })
+#define arch_write_trylock(lock)	({ barrier(); (void)(lock); 1; })
+#define arch_read_unlock(lock)		do { barrier(); (void)(lock); } while (0)
+#define arch_write_unlock(lock)	do { barrier(); (void)(lock); } while (0)
 
 #else /* DEBUG_SPINLOCK */
-#define __raw_spin_is_locked(lock)	((void)(lock), 0)
-/* for sched.c and kernel_lock.c: */
-# define __raw_spin_lock(lock)		do { (void)(lock); } while (0)
-# define __raw_spin_unlock(lock)	do { (void)(lock); } while (0)
-# define __raw_spin_trylock(lock)	({ (void)(lock); 1; })
+#define arch_spin_is_locked(lock)	((void)(lock), 0)
+/* for sched/core.c and kernel_lock.c: */
+# define arch_spin_lock(lock)		do { barrier(); (void)(lock); } while (0)
+# define arch_spin_lock_flags(lock, flags)	do { barrier(); (void)(lock); } while (0)
+# define arch_spin_unlock(lock)	do { barrier(); (void)(lock); } while (0)
+# define arch_spin_trylock(lock)	({ barrier(); (void)(lock); 1; })
 #endif /* DEBUG_SPINLOCK */
 
-#define __raw_spin_is_contended(lock)	(((void)(lock), 0))
+#define arch_spin_is_contended(lock)	(((void)(lock), 0))
 
-#define __raw_read_can_lock(lock)	(((void)(lock), 1))
-#define __raw_write_can_lock(lock)	(((void)(lock), 1))
+#define arch_read_can_lock(lock)	(((void)(lock), 1))
+#define arch_write_can_lock(lock)	(((void)(lock), 1))
 
-#define __raw_spin_unlock_wait(lock) \
-		do { cpu_relax(); } while (__raw_spin_is_locked(lock))
+#define arch_spin_unlock_wait(lock) \
+		do { cpu_relax(); } while (arch_spin_is_locked(lock))
 
 #endif /* __LINUX_SPINLOCK_UP_H */