From: David Howells <dhowells@redhat.com>
Date: Mon, 14 Mar 2011 14:49:44 +0000 (+0000)
Subject: MN10300: atomic_read() should ensure it emits a load
X-Git-Tag: firefly_0821_release~7613^2~2251^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=af794206542e03d62138a107ee0ffb5e7d631881;p=firefly-linux-kernel-4.4.55.git

MN10300: atomic_read() should ensure it emits a load

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>
---

diff --git a/arch/mn10300/include/asm/atomic.h b/arch/mn10300/include/asm/atomic.h
index 92d2f9298e38..9d773a639513 100644
--- a/arch/mn10300/include/asm/atomic.h
+++ b/arch/mn10300/include/asm/atomic.h
@@ -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