diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2015-09-18 11:13:10 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-09-23 09:54:28 +0200 |
| commit | 62e8a3258bda118f24ff462fe04cfbe75b8189b5 (patch) | |
| tree | 79edd4b96f8c3495435be8b148127d5738d1db63 /arch/arc | |
| parent | 90fe65148ea76988d8d5acbf3e578aa74129a490 (diff) | |
| download | linux-62e8a3258bda118f24ff462fe04cfbe75b8189b5.tar.bz2 | |
atomic, arch: Audit atomic_{read,set}()
This patch makes sure that atomic_{read,set}() are at least
{READ,WRITE}_ONCE().
We already had the 'requirement' that atomic_read() should use
ACCESS_ONCE(), and most archs had this, but a few were lacking.
All are now converted to use READ_ONCE().
And, by a symmetry and general paranoia argument, upgrade atomic_set()
to use WRITE_ONCE().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: james.hogan@imgtec.com
Cc: linux-kernel@vger.kernel.org
Cc: oleg@redhat.com
Cc: will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/arc')
| -rw-r--r-- | arch/arc/include/asm/atomic.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h index c3ecda023e3a..7730d302cadb 100644 --- a/arch/arc/include/asm/atomic.h +++ b/arch/arc/include/asm/atomic.h @@ -17,11 +17,11 @@ #include <asm/barrier.h> #include <asm/smp.h> -#define atomic_read(v) ((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) #ifdef CONFIG_ARC_HAS_LLSC -#define atomic_set(v, i) (((v)->counter) = (i)) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #ifdef CONFIG_ARC_STAR_9000923308 @@ -107,7 +107,7 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ #ifndef CONFIG_SMP /* violating atomic_xxx API locking protocol in UP for optimization sake */ -#define atomic_set(v, i) (((v)->counter) = (i)) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #else @@ -125,7 +125,7 @@ static inline void atomic_set(atomic_t *v, int i) unsigned long flags; atomic_ops_lock(flags); - v->counter = i; + WRITE_ONCE(v->counter, i); atomic_ops_unlock(flags); } |