sched_rt: don't use first_cpu on cpumask created with cpumask_and

cpumask_and() only initializes nr_cpu_ids bits, so the (deprecated)
first_cpu() might find one of those uninitialized bits if nr_cpu_ids
is less than NR_CPUS (as it can be for CONFIG_CPUMASK_OFFSTACK).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 954e1a81b796..bac1061cea2f 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -968,8 +968,8 @@ static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
         if ((this_cpu != -1) && cpu_isset(this_cpu, *mask))
                 return this_cpu;
 
-        first = first_cpu(*mask);
-        if (first != NR_CPUS)
+        first = cpumask_first(mask);
+        if (first < nr_cpu_ids)
                 return first;
 
         return -1;