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| 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 /include/asm-generic/atomic.h | |
| parent | atomic: Add atomic_long_t bitops (diff) | |
| download | linux-62e8a3258bda118f24ff462fe04cfbe75b8189b5.tar.xz linux-62e8a3258bda118f24ff462fe04cfbe75b8189b5.zip | |
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 'include/asm-generic/atomic.h')
| -rw-r--r-- | include/asm-generic/atomic.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h index d4d7e337fdcb..74f1a3704d7a 100644 --- a/include/asm-generic/atomic.h +++ b/include/asm-generic/atomic.h @@ -127,7 +127,7 @@ ATOMIC_OP(xor, ^) * Atomically reads the value of @v. */ #ifndef atomic_read -#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic_read(v) READ_ONCE((v)->counter) #endif /** @@ -137,7 +137,7 @@ ATOMIC_OP(xor, ^) * * Atomically sets the value of @v to @i. */ -#define atomic_set(v, i) (((v)->counter) = (i)) +#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i)) #include <linux/irqflags.h> |