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| author | Jarno Rajahalme <jrajahalme@nicira.com> | 2014-07-21 14:19:06 -0700 |
|---|---|---|
| committer | Jarno Rajahalme <jrajahalme@nicira.com> | 2014-07-21 14:19:06 -0700 |
| commit | 2924cf52ca105415762dc2c8ea8ba30f88b63f89 (patch) | |
| tree | 1462f6672173da9520e88d7af1011b9fa501fc04 | |
| parent | db73f7166a6baecbf07e8bb19451fb033954c5f6 (diff) | |
| download | openvswitch-2924cf52ca105415762dc2c8ea8ba30f88b63f89.tar.gz | |
lib/ovs-rcu: evaluate argument of ovsrcu_get only once.
As ovsrcu_get() looks like a function call, it is reasonable for the
callers to expect that the arguments are evaluated only once.
CONST_CAST expands its 'POINTER' argument multiple times, and the
exact effect of this turned out to be compiler dependent. Fix this by
expanding the macro argument before CONST_CAST, and removing
unnecessary CONST_CASTs.
VMware-BZ: #1287651
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
| -rw-r--r-- | lib/ovs-rcu.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/lib/ovs-rcu.h b/lib/ovs-rcu.h index 2c7d1ea78..96b323365 100644 --- a/lib/ovs-rcu.h +++ b/lib/ovs-rcu.h @@ -123,16 +123,17 @@ #define ovsrcu_get__(TYPE, VAR, ORDER) \ ({ \ TYPE value__; \ + typeof(VAR) ovsrcu_var = (VAR); \ \ - atomic_read_explicit(CONST_CAST(ATOMIC(TYPE) *, &(VAR)->p), \ + atomic_read_explicit(CONST_CAST(ATOMIC(TYPE) *, &ovsrcu_var->p), \ &value__, ORDER); \ \ value__; \ }) #define ovsrcu_get(TYPE, VAR) \ - CONST_CAST(TYPE, ovsrcu_get__(TYPE, VAR, memory_order_consume)) + ovsrcu_get__(TYPE, VAR, memory_order_consume) #define ovsrcu_get_protected(TYPE, VAR) \ - CONST_CAST(TYPE, ovsrcu_get__(TYPE, VAR, memory_order_relaxed)) + ovsrcu_get__(TYPE, VAR, memory_order_relaxed) /* 'VALUE' may be an atomic operation, which must be evaluated before * any of the body of the atomic_store_explicit. Since the type of |