rcu: Change _wait_rcu_gp() to work around GCC bug 67055
Code like this in inline functions confuses some recent versions of gcc:
const int n = const-expr;
whatever_t array[n];
For more details, see:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67055#c13
This compiler bug results in the following failure after 114b7fd4b (rcu:
Create rcu_sync infrastructure):
In file included from include/linux/rcupdate.h:429:0,
from include/linux/rcu_sync.h:5,
from kernel/rcu/sync.c:1:
include/linux/rcutiny.h: In function 'rcu_barrier_sched':
include/linux/rcutiny.h:55:20: internal compiler error: Segmentation fault
static inline void rcu_barrier_sched(void)
This commit therefore eliminates the constant local variable in favor of
direct use of the expression.
Reported-and-tested-by: Mark Salter <msalter@redhat.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index ff47651..581abf8 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -230,12 +230,11 @@
struct rcu_synchronize *rs_array);
#define _wait_rcu_gp(checktiny, ...) \
-do { \
- call_rcu_func_t __crcu_array[] = { __VA_ARGS__ }; \
- const int __n = ARRAY_SIZE(__crcu_array); \
- struct rcu_synchronize __rs_array[__n]; \
- \
- __wait_rcu_gp(checktiny, __n, __crcu_array, __rs_array); \
+do { \
+ call_rcu_func_t __crcu_array[] = { __VA_ARGS__ }; \
+ struct rcu_synchronize __rs_array[ARRAY_SIZE(__crcu_array)]; \
+ __wait_rcu_gp(checktiny, ARRAY_SIZE(__crcu_array), \
+ __crcu_array, __rs_array); \
} while (0)
#define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__)