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| author | Oleg Nesterov <oleg@redhat.com> | 2015-08-25 20:45:18 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-09-20 20:50:06 -0700 |
| commit | 66e8c57da6bf6b847a48a5a6fda59512f733ed78 (patch) | |
| tree | 42644ac73db43dfe197dad53763879ff4896cd0d /include/linux/rcupdate.h | |
| parent | 1f93e4a96c9109378204c147b3eec0d0e8100fde (diff) | |
| download | lwn-66e8c57da6bf6b847a48a5a6fda59512f733ed78.tar.gz lwn-66e8c57da6bf6b847a48a5a6fda59512f733ed78.zip | |
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>
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index ff476515f716..581abf848566 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -230,12 +230,11 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, 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__) |