4.4-stable review patch. If anyone has any objections, please let me know.
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From: Paul E. McKenney paulmck@linux.vnet.ibm.com
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@linux.vnet.ibm.com Cc: "Rantala, Tommi" tommi.t.rantala@nokia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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)]); }