x86: change _node_to_cpumask_ptr to return const ptr

  * Strengthen the return type for the _node_to_cpumask_ptr to be
    a const pointer.  This adds compiler checking to insure that
    node_to_cpumask_map[] is not changed inadvertently.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: "akpm@linux-foundation.org" <akpm@linux-foundation.org>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Acked-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 5fc310f746f..cac68430d31 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -343,23 +343,23 @@ static const cpumask_t cpu_mask_none;
 /*
  * Returns a pointer to the bitmask of CPUs on Node 'node'.
  */
-cpumask_t *_node_to_cpumask_ptr(int node)
+const cpumask_t *_node_to_cpumask_ptr(int node)
 {
 	if (node_to_cpumask_map == NULL) {
 		printk(KERN_WARNING
 			"_node_to_cpumask_ptr(%d): no node_to_cpumask_map!\n",
 			node);
 		dump_stack();
-		return &cpu_online_map;
+		return (const cpumask_t *)&cpu_online_map;
 	}
 	if (node >= nr_node_ids) {
 		printk(KERN_WARNING
 			"_node_to_cpumask_ptr(%d): node > nr_node_ids(%d)\n",
 			node, nr_node_ids);
 		dump_stack();
-		return (cpumask_t *)&cpu_mask_none;
+		return &cpu_mask_none;
 	}
-	return (cpumask_t *)&node_to_cpumask_map[node];
+	return &node_to_cpumask_map[node];
 }
 EXPORT_SYMBOL(_node_to_cpumask_ptr);