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| author | Alexander Gordeev <agordeev@redhat.com> | 2015-07-09 15:34:23 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-07-17 23:58:40 +0200 |
| commit | 032dfc87225c96ec1771e5967436c4b23d1dc5d6 (patch) | |
| tree | b37db4952f1bd658f7d7a62683aa94ae4b45417f /kernel/rcu/tree.h | |
| parent | rcu: Simplify arithmetic to calculate number of RCU nodes (diff) | |
| download | linux-032dfc87225c96ec1771e5967436c4b23d1dc5d6.tar.xz linux-032dfc87225c96ec1771e5967436c4b23d1dc5d6.zip | |
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@linux.vnet.ibm.com>
Suggested-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree.h')
| -rw-r--r-- | kernel/rcu/tree.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 581f8d3c5b28..faee5242d6ff 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. */ |