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 <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
mrcsosa · Feb 1, 2009 · 3d39870 · 3d39870
1 parent a571bbe
commit 3d39870
Showing 1 changed file with 2 additions and 2 deletions.
diff --git 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;