4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
commit ec3833ed02ae6ef2a933ece9de7cbab0c64c699e upstream.
The cpu_online() function can return values other than 0 and 1, which
can result in subscript overflow when applied to a two-element array.
This commit allows for this behavior by using "!!" on the return value
from cpu_online() when used as a subscript.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: "Rantala, Tommi" <tommi.t.rantala@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3817,7 +3817,7 @@ static void synchronize_sched_expedited_
continue;
rdp = per_cpu_ptr(rsp->rda, cpu);
pr_cont(" %d-%c%c%c", cpu,
- "O."[cpu_online(cpu)],
+ "O."[!!cpu_online(cpu)],
"o."[!!(rdp->grpmask & rnp->expmaskinit)],
"N."[!!(rdp->grpmask & rnp->expmaskinitnext)]);
}
