Commit-ID: 032dfc87225c96ec1771e5967436c4b23d1dc5d6
Gitweb: http://git.kernel.org/tip/032dfc87225c96ec1771e5967436c4b23d1dc5d6
Author: Alexander Gordeev <agordeev@xxxxxxxxxx>
AuthorDate: Thu, 9 Jul 2015 15:34:23 +0200
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Fri, 17 Jul 2015 14:58:40 -0700
rcu: Shut up bogus gcc array bounds warning
Because gcc does not realize a loop would not be entered ever
(i.e. in case of rcu_num_lvls == 1):
for (i = 1; i < rcu_num_lvls; i++)
rsp->level[i] = rsp->level[i - 1] + levelcnt[i - 1];
some compiler (pre- 5.x?) versions give a bogus warning:
kernel/rcu/tree.c: In function ‘rcu_init_one.isra.55’:
kernel/rcu/tree.c:4108:13: warning: array subscript is above array bounds [-Warray-bounds]
rsp->level[i] = rsp->level[i - 1] + rsp->levelcnt[i - 1];
^
Fix that warning by adding an extra item to rcu_state::level[]
array. Once the bogus warning is fixed in gcc and kernel drops
support of older versions, the dummy item may be removed from
the array.
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
Suggested-by: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 581f8d3..faee524 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -443,7 +443,9 @@ do { \
*/
struct rcu_state {
struct rcu_node node[NUM_RCU_NODES]; /* Hierarchy. */
- struct rcu_node *level[RCU_NUM_LVLS]; /* Hierarchy levels. */
+ struct rcu_node *level[RCU_NUM_LVLS + 1];
+ /* Hierarchy levels (+1 to */
+ /* shut bogus gcc warning) */
u8 flavor_mask; /* bit in flavor mask. */
struct rcu_data __percpu *rda; /* pointer of percu rcu_data. */
void (*call)(struct rcu_head *head, /* call_rcu() flavor. */
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|