[PATCH] sys_sched_setaffinity() on UP should fail for non-zero CPUs.

Return EINVAL for invalid sched_setaffinity on UP.  I was a little
surprised that sys_sched_setaffinity for CPU 1 didn't fail on my UP box.
With CONFIG_SMP it would have.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/sched.h

@@ -13,6 +13,7 @@
 #include <linux/rbtree.h>
 #include <linux/thread_info.h>
 #include <linux/cpumask.h>
+#include <linux/errno.h>
 
 #include <asm/system.h>
 #include <asm/semaphore.h>
@@ -732,6 +733,8 @@ extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
 #else
 static inline int set_cpus_allowed(task_t *p, cpumask_t new_mask)
 {
+	if (!cpus_intersects(new_mask, cpu_online_map))
+		return -EINVAL;
 	return 0;
 }
 #endif