MN10300: atomic_read() should ensure it emits a load
authorDavid Howells <dhowells@redhat.com>
Mon, 14 Mar 2011 14:49:44 +0000 (14:49 +0000)
committerDavid Howells <dhowells@redhat.com>
Mon, 14 Mar 2011 14:51:25 +0000 (14:51 +0000)
atomic_read() needs to ensure that it emits a load (which it can do by using
ACCESS_ONCE()).

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
arch/mn10300/include/asm/atomic.h

index 92d2f9298e3832155b14bf21d1eb964e015b87f5..9d773a639513abd3a35311a117a563912d52b236 100644 (file)
@@ -139,7 +139,7 @@ static inline unsigned long __cmpxchg(volatile unsigned long *m,
  * Atomically reads the value of @v.  Note that the guaranteed
  * useful range of an atomic_t is only 24 bits.
  */
-#define atomic_read(v) ((v)->counter)
+#define atomic_read(v) (ACCESS_ONCE((v)->counter))
 
 /**
  * atomic_set - set atomic variable