[PATCH 1/6] asm-generic: make atomic_add_unless a function

From: Arnd Bergmann
Date: Sat Oct 09 2010 - 15:58:23 EST


From: Mathieu Lacage <mathieu.lacage@xxxxxxxxxxxxxxx>

atomic_add_unless is a macro so, bad things happen if the caller defines
a local variable named c, just like like the local variable c defined by
the macro. Thus, convert atomic_add_unless to a function. (bug triggered
by net/ipv4/netfilter/ipt_CLUSTERIP.c: clusterip_config_find_get calls
atomic_inc_not_zero)

Signed-off-by: Mathieu Lacage <mathieu.lacage@xxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
include/asm-generic/atomic.h | 34 +++++++++++++++++-----------------
1 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h
index e53347f..a6cc019 100644
--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h
@@ -119,14 +119,23 @@ static inline void atomic_dec(atomic_t *v)
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)

-#define atomic_add_unless(v, a, u) \
-({ \
- int c, old; \
- c = atomic_read(v); \
- while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
- c = old; \
- c != (u); \
-})
+#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
+#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
+
+#define cmpxchg_local(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
+ (unsigned long)(n), sizeof(*(ptr))))
+
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+
+static inline int atomic_add_unless(atomic_t *v, int a, int u)
+{
+ int c, old;
+ c = atomic_read(v);
+ while (c != u && (old = atomic_cmpxchg(v, c, c + a)) != c)
+ c = old;
+ return c != u;
+}

#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)

@@ -140,15 +149,6 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
raw_local_irq_restore(flags);
}

-#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
-#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
-
-#define cmpxchg_local(ptr, o, n) \
- ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
- (unsigned long)(n), sizeof(*(ptr))))
-
-#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
-
/* Assume that atomic operations are already serializing */
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec() barrier()
--
1.7.1

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